xref: /linux/lib/vsprintf.c (revision 7f71507851fc7764b36a3221839607d3a45c2025)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *  linux/lib/vsprintf.c
4  *
5  *  Copyright (C) 1991, 1992  Linus Torvalds
6  */
7 
8 /* vsprintf.c -- Lars Wirzenius & Linus Torvalds. */
9 /*
10  * Wirzenius wrote this portably, Torvalds fucked it up :-)
11  */
12 
13 /*
14  * Fri Jul 13 2001 Crutcher Dunnavant <crutcher+kernel@datastacks.com>
15  * - changed to provide snprintf and vsnprintf functions
16  * So Feb  1 16:51:32 CET 2004 Juergen Quade <quade@hsnr.de>
17  * - scnprintf and vscnprintf
18  */
19 
20 #include <linux/stdarg.h>
21 #include <linux/build_bug.h>
22 #include <linux/clk.h>
23 #include <linux/clk-provider.h>
24 #include <linux/errname.h>
25 #include <linux/module.h>	/* for KSYM_SYMBOL_LEN */
26 #include <linux/types.h>
27 #include <linux/string.h>
28 #include <linux/ctype.h>
29 #include <linux/kernel.h>
30 #include <linux/kallsyms.h>
31 #include <linux/math64.h>
32 #include <linux/uaccess.h>
33 #include <linux/ioport.h>
34 #include <linux/dcache.h>
35 #include <linux/cred.h>
36 #include <linux/rtc.h>
37 #include <linux/sprintf.h>
38 #include <linux/time.h>
39 #include <linux/uuid.h>
40 #include <linux/of.h>
41 #include <net/addrconf.h>
42 #include <linux/siphash.h>
43 #include <linux/compiler.h>
44 #include <linux/property.h>
45 #include <linux/notifier.h>
46 #ifdef CONFIG_BLOCK
47 #include <linux/blkdev.h>
48 #endif
49 
50 #include "../mm/internal.h"	/* For the trace_print_flags arrays */
51 
52 #include <asm/page.h>		/* for PAGE_SIZE */
53 #include <asm/byteorder.h>	/* cpu_to_le16 */
54 #include <linux/unaligned.h>
55 
56 #include <linux/string_helpers.h>
57 #include "kstrtox.h"
58 
59 /* Disable pointer hashing if requested */
60 bool no_hash_pointers __ro_after_init;
61 EXPORT_SYMBOL_GPL(no_hash_pointers);
62 
63 noinline
64 static unsigned long long simple_strntoull(const char *startp, char **endp, unsigned int base, size_t max_chars)
65 {
66 	const char *cp;
67 	unsigned long long result = 0ULL;
68 	size_t prefix_chars;
69 	unsigned int rv;
70 
71 	cp = _parse_integer_fixup_radix(startp, &base);
72 	prefix_chars = cp - startp;
73 	if (prefix_chars < max_chars) {
74 		rv = _parse_integer_limit(cp, base, &result, max_chars - prefix_chars);
75 		/* FIXME */
76 		cp += (rv & ~KSTRTOX_OVERFLOW);
77 	} else {
78 		/* Field too short for prefix + digit, skip over without converting */
79 		cp = startp + max_chars;
80 	}
81 
82 	if (endp)
83 		*endp = (char *)cp;
84 
85 	return result;
86 }
87 
88 /**
89  * simple_strtoull - convert a string to an unsigned long long
90  * @cp: The start of the string
91  * @endp: A pointer to the end of the parsed string will be placed here
92  * @base: The number base to use
93  *
94  * This function has caveats. Please use kstrtoull instead.
95  */
96 noinline
97 unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base)
98 {
99 	return simple_strntoull(cp, endp, base, INT_MAX);
100 }
101 EXPORT_SYMBOL(simple_strtoull);
102 
103 /**
104  * simple_strtoul - convert a string to an unsigned long
105  * @cp: The start of the string
106  * @endp: A pointer to the end of the parsed string will be placed here
107  * @base: The number base to use
108  *
109  * This function has caveats. Please use kstrtoul instead.
110  */
111 unsigned long simple_strtoul(const char *cp, char **endp, unsigned int base)
112 {
113 	return simple_strtoull(cp, endp, base);
114 }
115 EXPORT_SYMBOL(simple_strtoul);
116 
117 /**
118  * simple_strtol - convert a string to a signed long
119  * @cp: The start of the string
120  * @endp: A pointer to the end of the parsed string will be placed here
121  * @base: The number base to use
122  *
123  * This function has caveats. Please use kstrtol instead.
124  */
125 long simple_strtol(const char *cp, char **endp, unsigned int base)
126 {
127 	if (*cp == '-')
128 		return -simple_strtoul(cp + 1, endp, base);
129 
130 	return simple_strtoul(cp, endp, base);
131 }
132 EXPORT_SYMBOL(simple_strtol);
133 
134 noinline
135 static long long simple_strntoll(const char *cp, char **endp, unsigned int base, size_t max_chars)
136 {
137 	/*
138 	 * simple_strntoull() safely handles receiving max_chars==0 in the
139 	 * case cp[0] == '-' && max_chars == 1.
140 	 * If max_chars == 0 we can drop through and pass it to simple_strntoull()
141 	 * and the content of *cp is irrelevant.
142 	 */
143 	if (*cp == '-' && max_chars > 0)
144 		return -simple_strntoull(cp + 1, endp, base, max_chars - 1);
145 
146 	return simple_strntoull(cp, endp, base, max_chars);
147 }
148 
149 /**
150  * simple_strtoll - convert a string to a signed long long
151  * @cp: The start of the string
152  * @endp: A pointer to the end of the parsed string will be placed here
153  * @base: The number base to use
154  *
155  * This function has caveats. Please use kstrtoll instead.
156  */
157 long long simple_strtoll(const char *cp, char **endp, unsigned int base)
158 {
159 	return simple_strntoll(cp, endp, base, INT_MAX);
160 }
161 EXPORT_SYMBOL(simple_strtoll);
162 
163 static noinline_for_stack
164 int skip_atoi(const char **s)
165 {
166 	int i = 0;
167 
168 	do {
169 		i = i*10 + *((*s)++) - '0';
170 	} while (isdigit(**s));
171 
172 	return i;
173 }
174 
175 /*
176  * Decimal conversion is by far the most typical, and is used for
177  * /proc and /sys data. This directly impacts e.g. top performance
178  * with many processes running. We optimize it for speed by emitting
179  * two characters at a time, using a 200 byte lookup table. This
180  * roughly halves the number of multiplications compared to computing
181  * the digits one at a time. Implementation strongly inspired by the
182  * previous version, which in turn used ideas described at
183  * <http://www.cs.uiowa.edu/~jones/bcd/divide.html> (with permission
184  * from the author, Douglas W. Jones).
185  *
186  * It turns out there is precisely one 26 bit fixed-point
187  * approximation a of 64/100 for which x/100 == (x * (u64)a) >> 32
188  * holds for all x in [0, 10^8-1], namely a = 0x28f5c29. The actual
189  * range happens to be somewhat larger (x <= 1073741898), but that's
190  * irrelevant for our purpose.
191  *
192  * For dividing a number in the range [10^4, 10^6-1] by 100, we still
193  * need a 32x32->64 bit multiply, so we simply use the same constant.
194  *
195  * For dividing a number in the range [100, 10^4-1] by 100, there are
196  * several options. The simplest is (x * 0x147b) >> 19, which is valid
197  * for all x <= 43698.
198  */
199 
200 static const u16 decpair[100] = {
201 #define _(x) (__force u16) cpu_to_le16(((x % 10) | ((x / 10) << 8)) + 0x3030)
202 	_( 0), _( 1), _( 2), _( 3), _( 4), _( 5), _( 6), _( 7), _( 8), _( 9),
203 	_(10), _(11), _(12), _(13), _(14), _(15), _(16), _(17), _(18), _(19),
204 	_(20), _(21), _(22), _(23), _(24), _(25), _(26), _(27), _(28), _(29),
205 	_(30), _(31), _(32), _(33), _(34), _(35), _(36), _(37), _(38), _(39),
206 	_(40), _(41), _(42), _(43), _(44), _(45), _(46), _(47), _(48), _(49),
207 	_(50), _(51), _(52), _(53), _(54), _(55), _(56), _(57), _(58), _(59),
208 	_(60), _(61), _(62), _(63), _(64), _(65), _(66), _(67), _(68), _(69),
209 	_(70), _(71), _(72), _(73), _(74), _(75), _(76), _(77), _(78), _(79),
210 	_(80), _(81), _(82), _(83), _(84), _(85), _(86), _(87), _(88), _(89),
211 	_(90), _(91), _(92), _(93), _(94), _(95), _(96), _(97), _(98), _(99),
212 #undef _
213 };
214 
215 /*
216  * This will print a single '0' even if r == 0, since we would
217  * immediately jump to out_r where two 0s would be written but only
218  * one of them accounted for in buf. This is needed by ip4_string
219  * below. All other callers pass a non-zero value of r.
220 */
221 static noinline_for_stack
222 char *put_dec_trunc8(char *buf, unsigned r)
223 {
224 	unsigned q;
225 
226 	/* 1 <= r < 10^8 */
227 	if (r < 100)
228 		goto out_r;
229 
230 	/* 100 <= r < 10^8 */
231 	q = (r * (u64)0x28f5c29) >> 32;
232 	*((u16 *)buf) = decpair[r - 100*q];
233 	buf += 2;
234 
235 	/* 1 <= q < 10^6 */
236 	if (q < 100)
237 		goto out_q;
238 
239 	/*  100 <= q < 10^6 */
240 	r = (q * (u64)0x28f5c29) >> 32;
241 	*((u16 *)buf) = decpair[q - 100*r];
242 	buf += 2;
243 
244 	/* 1 <= r < 10^4 */
245 	if (r < 100)
246 		goto out_r;
247 
248 	/* 100 <= r < 10^4 */
249 	q = (r * 0x147b) >> 19;
250 	*((u16 *)buf) = decpair[r - 100*q];
251 	buf += 2;
252 out_q:
253 	/* 1 <= q < 100 */
254 	r = q;
255 out_r:
256 	/* 1 <= r < 100 */
257 	*((u16 *)buf) = decpair[r];
258 	buf += r < 10 ? 1 : 2;
259 	return buf;
260 }
261 
262 #if BITS_PER_LONG == 64 && BITS_PER_LONG_LONG == 64
263 static noinline_for_stack
264 char *put_dec_full8(char *buf, unsigned r)
265 {
266 	unsigned q;
267 
268 	/* 0 <= r < 10^8 */
269 	q = (r * (u64)0x28f5c29) >> 32;
270 	*((u16 *)buf) = decpair[r - 100*q];
271 	buf += 2;
272 
273 	/* 0 <= q < 10^6 */
274 	r = (q * (u64)0x28f5c29) >> 32;
275 	*((u16 *)buf) = decpair[q - 100*r];
276 	buf += 2;
277 
278 	/* 0 <= r < 10^4 */
279 	q = (r * 0x147b) >> 19;
280 	*((u16 *)buf) = decpair[r - 100*q];
281 	buf += 2;
282 
283 	/* 0 <= q < 100 */
284 	*((u16 *)buf) = decpair[q];
285 	buf += 2;
286 	return buf;
287 }
288 
289 static noinline_for_stack
290 char *put_dec(char *buf, unsigned long long n)
291 {
292 	if (n >= 100*1000*1000)
293 		buf = put_dec_full8(buf, do_div(n, 100*1000*1000));
294 	/* 1 <= n <= 1.6e11 */
295 	if (n >= 100*1000*1000)
296 		buf = put_dec_full8(buf, do_div(n, 100*1000*1000));
297 	/* 1 <= n < 1e8 */
298 	return put_dec_trunc8(buf, n);
299 }
300 
301 #elif BITS_PER_LONG == 32 && BITS_PER_LONG_LONG == 64
302 
303 static void
304 put_dec_full4(char *buf, unsigned r)
305 {
306 	unsigned q;
307 
308 	/* 0 <= r < 10^4 */
309 	q = (r * 0x147b) >> 19;
310 	*((u16 *)buf) = decpair[r - 100*q];
311 	buf += 2;
312 	/* 0 <= q < 100 */
313 	*((u16 *)buf) = decpair[q];
314 }
315 
316 /*
317  * Call put_dec_full4 on x % 10000, return x / 10000.
318  * The approximation x/10000 == (x * 0x346DC5D7) >> 43
319  * holds for all x < 1,128,869,999.  The largest value this
320  * helper will ever be asked to convert is 1,125,520,955.
321  * (second call in the put_dec code, assuming n is all-ones).
322  */
323 static noinline_for_stack
324 unsigned put_dec_helper4(char *buf, unsigned x)
325 {
326         uint32_t q = (x * (uint64_t)0x346DC5D7) >> 43;
327 
328         put_dec_full4(buf, x - q * 10000);
329         return q;
330 }
331 
332 /* Based on code by Douglas W. Jones found at
333  * <http://www.cs.uiowa.edu/~jones/bcd/decimal.html#sixtyfour>
334  * (with permission from the author).
335  * Performs no 64-bit division and hence should be fast on 32-bit machines.
336  */
337 static
338 char *put_dec(char *buf, unsigned long long n)
339 {
340 	uint32_t d3, d2, d1, q, h;
341 
342 	if (n < 100*1000*1000)
343 		return put_dec_trunc8(buf, n);
344 
345 	d1  = ((uint32_t)n >> 16); /* implicit "& 0xffff" */
346 	h   = (n >> 32);
347 	d2  = (h      ) & 0xffff;
348 	d3  = (h >> 16); /* implicit "& 0xffff" */
349 
350 	/* n = 2^48 d3 + 2^32 d2 + 2^16 d1 + d0
351 	     = 281_4749_7671_0656 d3 + 42_9496_7296 d2 + 6_5536 d1 + d0 */
352 	q   = 656 * d3 + 7296 * d2 + 5536 * d1 + ((uint32_t)n & 0xffff);
353 	q = put_dec_helper4(buf, q);
354 
355 	q += 7671 * d3 + 9496 * d2 + 6 * d1;
356 	q = put_dec_helper4(buf+4, q);
357 
358 	q += 4749 * d3 + 42 * d2;
359 	q = put_dec_helper4(buf+8, q);
360 
361 	q += 281 * d3;
362 	buf += 12;
363 	if (q)
364 		buf = put_dec_trunc8(buf, q);
365 	else while (buf[-1] == '0')
366 		--buf;
367 
368 	return buf;
369 }
370 
371 #endif
372 
373 /*
374  * Convert passed number to decimal string.
375  * Returns the length of string.  On buffer overflow, returns 0.
376  *
377  * If speed is not important, use snprintf(). It's easy to read the code.
378  */
379 int num_to_str(char *buf, int size, unsigned long long num, unsigned int width)
380 {
381 	/* put_dec requires 2-byte alignment of the buffer. */
382 	char tmp[sizeof(num) * 3] __aligned(2);
383 	int idx, len;
384 
385 	/* put_dec() may work incorrectly for num = 0 (generate "", not "0") */
386 	if (num <= 9) {
387 		tmp[0] = '0' + num;
388 		len = 1;
389 	} else {
390 		len = put_dec(tmp, num) - tmp;
391 	}
392 
393 	if (len > size || width > size)
394 		return 0;
395 
396 	if (width > len) {
397 		width = width - len;
398 		for (idx = 0; idx < width; idx++)
399 			buf[idx] = ' ';
400 	} else {
401 		width = 0;
402 	}
403 
404 	for (idx = 0; idx < len; ++idx)
405 		buf[idx + width] = tmp[len - idx - 1];
406 
407 	return len + width;
408 }
409 
410 #define SIGN	1		/* unsigned/signed, must be 1 */
411 #define LEFT	2		/* left justified */
412 #define PLUS	4		/* show plus */
413 #define SPACE	8		/* space if plus */
414 #define ZEROPAD	16		/* pad with zero, must be 16 == '0' - ' ' */
415 #define SMALL	32		/* use lowercase in hex (must be 32 == 0x20) */
416 #define SPECIAL	64		/* prefix hex with "0x", octal with "0" */
417 
418 static_assert(SIGN == 1);
419 static_assert(ZEROPAD == ('0' - ' '));
420 static_assert(SMALL == ('a' ^ 'A'));
421 
422 enum format_type {
423 	FORMAT_TYPE_NONE, /* Just a string part */
424 	FORMAT_TYPE_WIDTH,
425 	FORMAT_TYPE_PRECISION,
426 	FORMAT_TYPE_CHAR,
427 	FORMAT_TYPE_STR,
428 	FORMAT_TYPE_PTR,
429 	FORMAT_TYPE_PERCENT_CHAR,
430 	FORMAT_TYPE_INVALID,
431 	FORMAT_TYPE_LONG_LONG,
432 	FORMAT_TYPE_ULONG,
433 	FORMAT_TYPE_LONG,
434 	FORMAT_TYPE_UBYTE,
435 	FORMAT_TYPE_BYTE,
436 	FORMAT_TYPE_USHORT,
437 	FORMAT_TYPE_SHORT,
438 	FORMAT_TYPE_UINT,
439 	FORMAT_TYPE_INT,
440 	FORMAT_TYPE_SIZE_T,
441 	FORMAT_TYPE_PTRDIFF
442 };
443 
444 struct printf_spec {
445 	unsigned int	type:8;		/* format_type enum */
446 	signed int	field_width:24;	/* width of output field */
447 	unsigned int	flags:8;	/* flags to number() */
448 	unsigned int	base:8;		/* number base, 8, 10 or 16 only */
449 	signed int	precision:16;	/* # of digits/chars */
450 } __packed;
451 static_assert(sizeof(struct printf_spec) == 8);
452 
453 #define FIELD_WIDTH_MAX ((1 << 23) - 1)
454 #define PRECISION_MAX ((1 << 15) - 1)
455 
456 static noinline_for_stack
457 char *number(char *buf, char *end, unsigned long long num,
458 	     struct printf_spec spec)
459 {
460 	/* put_dec requires 2-byte alignment of the buffer. */
461 	char tmp[3 * sizeof(num)] __aligned(2);
462 	char sign;
463 	char locase;
464 	int need_pfx = ((spec.flags & SPECIAL) && spec.base != 10);
465 	int i;
466 	bool is_zero = num == 0LL;
467 	int field_width = spec.field_width;
468 	int precision = spec.precision;
469 
470 	/* locase = 0 or 0x20. ORing digits or letters with 'locase'
471 	 * produces same digits or (maybe lowercased) letters */
472 	locase = (spec.flags & SMALL);
473 	if (spec.flags & LEFT)
474 		spec.flags &= ~ZEROPAD;
475 	sign = 0;
476 	if (spec.flags & SIGN) {
477 		if ((signed long long)num < 0) {
478 			sign = '-';
479 			num = -(signed long long)num;
480 			field_width--;
481 		} else if (spec.flags & PLUS) {
482 			sign = '+';
483 			field_width--;
484 		} else if (spec.flags & SPACE) {
485 			sign = ' ';
486 			field_width--;
487 		}
488 	}
489 	if (need_pfx) {
490 		if (spec.base == 16)
491 			field_width -= 2;
492 		else if (!is_zero)
493 			field_width--;
494 	}
495 
496 	/* generate full string in tmp[], in reverse order */
497 	i = 0;
498 	if (num < spec.base)
499 		tmp[i++] = hex_asc_upper[num] | locase;
500 	else if (spec.base != 10) { /* 8 or 16 */
501 		int mask = spec.base - 1;
502 		int shift = 3;
503 
504 		if (spec.base == 16)
505 			shift = 4;
506 		do {
507 			tmp[i++] = (hex_asc_upper[((unsigned char)num) & mask] | locase);
508 			num >>= shift;
509 		} while (num);
510 	} else { /* base 10 */
511 		i = put_dec(tmp, num) - tmp;
512 	}
513 
514 	/* printing 100 using %2d gives "100", not "00" */
515 	if (i > precision)
516 		precision = i;
517 	/* leading space padding */
518 	field_width -= precision;
519 	if (!(spec.flags & (ZEROPAD | LEFT))) {
520 		while (--field_width >= 0) {
521 			if (buf < end)
522 				*buf = ' ';
523 			++buf;
524 		}
525 	}
526 	/* sign */
527 	if (sign) {
528 		if (buf < end)
529 			*buf = sign;
530 		++buf;
531 	}
532 	/* "0x" / "0" prefix */
533 	if (need_pfx) {
534 		if (spec.base == 16 || !is_zero) {
535 			if (buf < end)
536 				*buf = '0';
537 			++buf;
538 		}
539 		if (spec.base == 16) {
540 			if (buf < end)
541 				*buf = ('X' | locase);
542 			++buf;
543 		}
544 	}
545 	/* zero or space padding */
546 	if (!(spec.flags & LEFT)) {
547 		char c = ' ' + (spec.flags & ZEROPAD);
548 
549 		while (--field_width >= 0) {
550 			if (buf < end)
551 				*buf = c;
552 			++buf;
553 		}
554 	}
555 	/* hmm even more zero padding? */
556 	while (i <= --precision) {
557 		if (buf < end)
558 			*buf = '0';
559 		++buf;
560 	}
561 	/* actual digits of result */
562 	while (--i >= 0) {
563 		if (buf < end)
564 			*buf = tmp[i];
565 		++buf;
566 	}
567 	/* trailing space padding */
568 	while (--field_width >= 0) {
569 		if (buf < end)
570 			*buf = ' ';
571 		++buf;
572 	}
573 
574 	return buf;
575 }
576 
577 static noinline_for_stack
578 char *special_hex_number(char *buf, char *end, unsigned long long num, int size)
579 {
580 	struct printf_spec spec;
581 
582 	spec.type = FORMAT_TYPE_PTR;
583 	spec.field_width = 2 + 2 * size;	/* 0x + hex */
584 	spec.flags = SPECIAL | SMALL | ZEROPAD;
585 	spec.base = 16;
586 	spec.precision = -1;
587 
588 	return number(buf, end, num, spec);
589 }
590 
591 static void move_right(char *buf, char *end, unsigned len, unsigned spaces)
592 {
593 	size_t size;
594 	if (buf >= end)	/* nowhere to put anything */
595 		return;
596 	size = end - buf;
597 	if (size <= spaces) {
598 		memset(buf, ' ', size);
599 		return;
600 	}
601 	if (len) {
602 		if (len > size - spaces)
603 			len = size - spaces;
604 		memmove(buf + spaces, buf, len);
605 	}
606 	memset(buf, ' ', spaces);
607 }
608 
609 /*
610  * Handle field width padding for a string.
611  * @buf: current buffer position
612  * @n: length of string
613  * @end: end of output buffer
614  * @spec: for field width and flags
615  * Returns: new buffer position after padding.
616  */
617 static noinline_for_stack
618 char *widen_string(char *buf, int n, char *end, struct printf_spec spec)
619 {
620 	unsigned spaces;
621 
622 	if (likely(n >= spec.field_width))
623 		return buf;
624 	/* we want to pad the sucker */
625 	spaces = spec.field_width - n;
626 	if (!(spec.flags & LEFT)) {
627 		move_right(buf - n, end, n, spaces);
628 		return buf + spaces;
629 	}
630 	while (spaces--) {
631 		if (buf < end)
632 			*buf = ' ';
633 		++buf;
634 	}
635 	return buf;
636 }
637 
638 /* Handle string from a well known address. */
639 static char *string_nocheck(char *buf, char *end, const char *s,
640 			    struct printf_spec spec)
641 {
642 	int len = 0;
643 	int lim = spec.precision;
644 
645 	while (lim--) {
646 		char c = *s++;
647 		if (!c)
648 			break;
649 		if (buf < end)
650 			*buf = c;
651 		++buf;
652 		++len;
653 	}
654 	return widen_string(buf, len, end, spec);
655 }
656 
657 static char *err_ptr(char *buf, char *end, void *ptr,
658 		     struct printf_spec spec)
659 {
660 	int err = PTR_ERR(ptr);
661 	const char *sym = errname(err);
662 
663 	if (sym)
664 		return string_nocheck(buf, end, sym, spec);
665 
666 	/*
667 	 * Somebody passed ERR_PTR(-1234) or some other non-existing
668 	 * Efoo - or perhaps CONFIG_SYMBOLIC_ERRNAME=n. Fall back to
669 	 * printing it as its decimal representation.
670 	 */
671 	spec.flags |= SIGN;
672 	spec.base = 10;
673 	return number(buf, end, err, spec);
674 }
675 
676 /* Be careful: error messages must fit into the given buffer. */
677 static char *error_string(char *buf, char *end, const char *s,
678 			  struct printf_spec spec)
679 {
680 	/*
681 	 * Hard limit to avoid a completely insane messages. It actually
682 	 * works pretty well because most error messages are in
683 	 * the many pointer format modifiers.
684 	 */
685 	if (spec.precision == -1)
686 		spec.precision = 2 * sizeof(void *);
687 
688 	return string_nocheck(buf, end, s, spec);
689 }
690 
691 /*
692  * Do not call any complex external code here. Nested printk()/vsprintf()
693  * might cause infinite loops. Failures might break printk() and would
694  * be hard to debug.
695  */
696 static const char *check_pointer_msg(const void *ptr)
697 {
698 	if (!ptr)
699 		return "(null)";
700 
701 	if ((unsigned long)ptr < PAGE_SIZE || IS_ERR_VALUE(ptr))
702 		return "(efault)";
703 
704 	return NULL;
705 }
706 
707 static int check_pointer(char **buf, char *end, const void *ptr,
708 			 struct printf_spec spec)
709 {
710 	const char *err_msg;
711 
712 	err_msg = check_pointer_msg(ptr);
713 	if (err_msg) {
714 		*buf = error_string(*buf, end, err_msg, spec);
715 		return -EFAULT;
716 	}
717 
718 	return 0;
719 }
720 
721 static noinline_for_stack
722 char *string(char *buf, char *end, const char *s,
723 	     struct printf_spec spec)
724 {
725 	if (check_pointer(&buf, end, s, spec))
726 		return buf;
727 
728 	return string_nocheck(buf, end, s, spec);
729 }
730 
731 static char *pointer_string(char *buf, char *end,
732 			    const void *ptr,
733 			    struct printf_spec spec)
734 {
735 	spec.base = 16;
736 	spec.flags |= SMALL;
737 	if (spec.field_width == -1) {
738 		spec.field_width = 2 * sizeof(ptr);
739 		spec.flags |= ZEROPAD;
740 	}
741 
742 	return number(buf, end, (unsigned long int)ptr, spec);
743 }
744 
745 /* Make pointers available for printing early in the boot sequence. */
746 static int debug_boot_weak_hash __ro_after_init;
747 
748 static int __init debug_boot_weak_hash_enable(char *str)
749 {
750 	debug_boot_weak_hash = 1;
751 	pr_info("debug_boot_weak_hash enabled\n");
752 	return 0;
753 }
754 early_param("debug_boot_weak_hash", debug_boot_weak_hash_enable);
755 
756 static bool filled_random_ptr_key __read_mostly;
757 static siphash_key_t ptr_key __read_mostly;
758 
759 static int fill_ptr_key(struct notifier_block *nb, unsigned long action, void *data)
760 {
761 	get_random_bytes(&ptr_key, sizeof(ptr_key));
762 
763 	/* Pairs with smp_rmb() before reading ptr_key. */
764 	smp_wmb();
765 	WRITE_ONCE(filled_random_ptr_key, true);
766 	return NOTIFY_DONE;
767 }
768 
769 static int __init vsprintf_init_hashval(void)
770 {
771 	static struct notifier_block fill_ptr_key_nb = { .notifier_call = fill_ptr_key };
772 	execute_with_initialized_rng(&fill_ptr_key_nb);
773 	return 0;
774 }
775 subsys_initcall(vsprintf_init_hashval)
776 
777 /* Maps a pointer to a 32 bit unique identifier. */
778 static inline int __ptr_to_hashval(const void *ptr, unsigned long *hashval_out)
779 {
780 	unsigned long hashval;
781 
782 	if (!READ_ONCE(filled_random_ptr_key))
783 		return -EBUSY;
784 
785 	/* Pairs with smp_wmb() after writing ptr_key. */
786 	smp_rmb();
787 
788 #ifdef CONFIG_64BIT
789 	hashval = (unsigned long)siphash_1u64((u64)ptr, &ptr_key);
790 	/*
791 	 * Mask off the first 32 bits, this makes explicit that we have
792 	 * modified the address (and 32 bits is plenty for a unique ID).
793 	 */
794 	hashval = hashval & 0xffffffff;
795 #else
796 	hashval = (unsigned long)siphash_1u32((u32)ptr, &ptr_key);
797 #endif
798 	*hashval_out = hashval;
799 	return 0;
800 }
801 
802 int ptr_to_hashval(const void *ptr, unsigned long *hashval_out)
803 {
804 	return __ptr_to_hashval(ptr, hashval_out);
805 }
806 
807 static char *ptr_to_id(char *buf, char *end, const void *ptr,
808 		       struct printf_spec spec)
809 {
810 	const char *str = sizeof(ptr) == 8 ? "(____ptrval____)" : "(ptrval)";
811 	unsigned long hashval;
812 	int ret;
813 
814 	/*
815 	 * Print the real pointer value for NULL and error pointers,
816 	 * as they are not actual addresses.
817 	 */
818 	if (IS_ERR_OR_NULL(ptr))
819 		return pointer_string(buf, end, ptr, spec);
820 
821 	/* When debugging early boot use non-cryptographically secure hash. */
822 	if (unlikely(debug_boot_weak_hash)) {
823 		hashval = hash_long((unsigned long)ptr, 32);
824 		return pointer_string(buf, end, (const void *)hashval, spec);
825 	}
826 
827 	ret = __ptr_to_hashval(ptr, &hashval);
828 	if (ret) {
829 		spec.field_width = 2 * sizeof(ptr);
830 		/* string length must be less than default_width */
831 		return error_string(buf, end, str, spec);
832 	}
833 
834 	return pointer_string(buf, end, (const void *)hashval, spec);
835 }
836 
837 static char *default_pointer(char *buf, char *end, const void *ptr,
838 			     struct printf_spec spec)
839 {
840 	/*
841 	 * default is to _not_ leak addresses, so hash before printing,
842 	 * unless no_hash_pointers is specified on the command line.
843 	 */
844 	if (unlikely(no_hash_pointers))
845 		return pointer_string(buf, end, ptr, spec);
846 
847 	return ptr_to_id(buf, end, ptr, spec);
848 }
849 
850 int kptr_restrict __read_mostly;
851 
852 static noinline_for_stack
853 char *restricted_pointer(char *buf, char *end, const void *ptr,
854 			 struct printf_spec spec)
855 {
856 	switch (kptr_restrict) {
857 	case 0:
858 		/* Handle as %p, hash and do _not_ leak addresses. */
859 		return default_pointer(buf, end, ptr, spec);
860 	case 1: {
861 		const struct cred *cred;
862 
863 		/*
864 		 * kptr_restrict==1 cannot be used in IRQ context
865 		 * because its test for CAP_SYSLOG would be meaningless.
866 		 */
867 		if (in_hardirq() || in_serving_softirq() || in_nmi()) {
868 			if (spec.field_width == -1)
869 				spec.field_width = 2 * sizeof(ptr);
870 			return error_string(buf, end, "pK-error", spec);
871 		}
872 
873 		/*
874 		 * Only print the real pointer value if the current
875 		 * process has CAP_SYSLOG and is running with the
876 		 * same credentials it started with. This is because
877 		 * access to files is checked at open() time, but %pK
878 		 * checks permission at read() time. We don't want to
879 		 * leak pointer values if a binary opens a file using
880 		 * %pK and then elevates privileges before reading it.
881 		 */
882 		cred = current_cred();
883 		if (!has_capability_noaudit(current, CAP_SYSLOG) ||
884 		    !uid_eq(cred->euid, cred->uid) ||
885 		    !gid_eq(cred->egid, cred->gid))
886 			ptr = NULL;
887 		break;
888 	}
889 	case 2:
890 	default:
891 		/* Always print 0's for %pK */
892 		ptr = NULL;
893 		break;
894 	}
895 
896 	return pointer_string(buf, end, ptr, spec);
897 }
898 
899 static noinline_for_stack
900 char *dentry_name(char *buf, char *end, const struct dentry *d, struct printf_spec spec,
901 		  const char *fmt)
902 {
903 	const char *array[4], *s;
904 	const struct dentry *p;
905 	int depth;
906 	int i, n;
907 
908 	switch (fmt[1]) {
909 		case '2': case '3': case '4':
910 			depth = fmt[1] - '0';
911 			break;
912 		default:
913 			depth = 1;
914 	}
915 
916 	rcu_read_lock();
917 	for (i = 0; i < depth; i++, d = p) {
918 		if (check_pointer(&buf, end, d, spec)) {
919 			rcu_read_unlock();
920 			return buf;
921 		}
922 
923 		p = READ_ONCE(d->d_parent);
924 		array[i] = READ_ONCE(d->d_name.name);
925 		if (p == d) {
926 			if (i)
927 				array[i] = "";
928 			i++;
929 			break;
930 		}
931 	}
932 	s = array[--i];
933 	for (n = 0; n != spec.precision; n++, buf++) {
934 		char c = *s++;
935 		if (!c) {
936 			if (!i)
937 				break;
938 			c = '/';
939 			s = array[--i];
940 		}
941 		if (buf < end)
942 			*buf = c;
943 	}
944 	rcu_read_unlock();
945 	return widen_string(buf, n, end, spec);
946 }
947 
948 static noinline_for_stack
949 char *file_dentry_name(char *buf, char *end, const struct file *f,
950 			struct printf_spec spec, const char *fmt)
951 {
952 	if (check_pointer(&buf, end, f, spec))
953 		return buf;
954 
955 	return dentry_name(buf, end, f->f_path.dentry, spec, fmt);
956 }
957 #ifdef CONFIG_BLOCK
958 static noinline_for_stack
959 char *bdev_name(char *buf, char *end, struct block_device *bdev,
960 		struct printf_spec spec, const char *fmt)
961 {
962 	struct gendisk *hd;
963 
964 	if (check_pointer(&buf, end, bdev, spec))
965 		return buf;
966 
967 	hd = bdev->bd_disk;
968 	buf = string(buf, end, hd->disk_name, spec);
969 	if (bdev_is_partition(bdev)) {
970 		if (isdigit(hd->disk_name[strlen(hd->disk_name)-1])) {
971 			if (buf < end)
972 				*buf = 'p';
973 			buf++;
974 		}
975 		buf = number(buf, end, bdev_partno(bdev), spec);
976 	}
977 	return buf;
978 }
979 #endif
980 
981 static noinline_for_stack
982 char *symbol_string(char *buf, char *end, void *ptr,
983 		    struct printf_spec spec, const char *fmt)
984 {
985 	unsigned long value;
986 #ifdef CONFIG_KALLSYMS
987 	char sym[KSYM_SYMBOL_LEN];
988 #endif
989 
990 	if (fmt[1] == 'R')
991 		ptr = __builtin_extract_return_addr(ptr);
992 	value = (unsigned long)ptr;
993 
994 #ifdef CONFIG_KALLSYMS
995 	if (*fmt == 'B' && fmt[1] == 'b')
996 		sprint_backtrace_build_id(sym, value);
997 	else if (*fmt == 'B')
998 		sprint_backtrace(sym, value);
999 	else if (*fmt == 'S' && (fmt[1] == 'b' || (fmt[1] == 'R' && fmt[2] == 'b')))
1000 		sprint_symbol_build_id(sym, value);
1001 	else if (*fmt != 's')
1002 		sprint_symbol(sym, value);
1003 	else
1004 		sprint_symbol_no_offset(sym, value);
1005 
1006 	return string_nocheck(buf, end, sym, spec);
1007 #else
1008 	return special_hex_number(buf, end, value, sizeof(void *));
1009 #endif
1010 }
1011 
1012 static const struct printf_spec default_str_spec = {
1013 	.field_width = -1,
1014 	.precision = -1,
1015 };
1016 
1017 static const struct printf_spec default_flag_spec = {
1018 	.base = 16,
1019 	.precision = -1,
1020 	.flags = SPECIAL | SMALL,
1021 };
1022 
1023 static const struct printf_spec default_dec_spec = {
1024 	.base = 10,
1025 	.precision = -1,
1026 };
1027 
1028 static const struct printf_spec default_dec02_spec = {
1029 	.base = 10,
1030 	.field_width = 2,
1031 	.precision = -1,
1032 	.flags = ZEROPAD,
1033 };
1034 
1035 static const struct printf_spec default_dec04_spec = {
1036 	.base = 10,
1037 	.field_width = 4,
1038 	.precision = -1,
1039 	.flags = ZEROPAD,
1040 };
1041 
1042 static noinline_for_stack
1043 char *hex_range(char *buf, char *end, u64 start_val, u64 end_val,
1044 		struct printf_spec spec)
1045 {
1046 	buf = number(buf, end, start_val, spec);
1047 	if (start_val == end_val)
1048 		return buf;
1049 
1050 	if (buf < end)
1051 		*buf = '-';
1052 	++buf;
1053 	return number(buf, end, end_val, spec);
1054 }
1055 
1056 static noinline_for_stack
1057 char *resource_string(char *buf, char *end, struct resource *res,
1058 		      struct printf_spec spec, const char *fmt)
1059 {
1060 #ifndef IO_RSRC_PRINTK_SIZE
1061 #define IO_RSRC_PRINTK_SIZE	6
1062 #endif
1063 
1064 #ifndef MEM_RSRC_PRINTK_SIZE
1065 #define MEM_RSRC_PRINTK_SIZE	10
1066 #endif
1067 	static const struct printf_spec io_spec = {
1068 		.base = 16,
1069 		.field_width = IO_RSRC_PRINTK_SIZE,
1070 		.precision = -1,
1071 		.flags = SPECIAL | SMALL | ZEROPAD,
1072 	};
1073 	static const struct printf_spec mem_spec = {
1074 		.base = 16,
1075 		.field_width = MEM_RSRC_PRINTK_SIZE,
1076 		.precision = -1,
1077 		.flags = SPECIAL | SMALL | ZEROPAD,
1078 	};
1079 	static const struct printf_spec bus_spec = {
1080 		.base = 16,
1081 		.field_width = 2,
1082 		.precision = -1,
1083 		.flags = SMALL | ZEROPAD,
1084 	};
1085 	static const struct printf_spec str_spec = {
1086 		.field_width = -1,
1087 		.precision = 10,
1088 		.flags = LEFT,
1089 	};
1090 
1091 	/* 32-bit res (sizeof==4): 10 chars in dec, 10 in hex ("0x" + 8)
1092 	 * 64-bit res (sizeof==8): 20 chars in dec, 18 in hex ("0x" + 16) */
1093 #define RSRC_BUF_SIZE		((2 * sizeof(resource_size_t)) + 4)
1094 #define FLAG_BUF_SIZE		(2 * sizeof(res->flags))
1095 #define DECODED_BUF_SIZE	sizeof("[mem - 64bit pref window disabled]")
1096 #define RAW_BUF_SIZE		sizeof("[mem - flags 0x]")
1097 	char sym[MAX(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE,
1098 		     2*RSRC_BUF_SIZE + FLAG_BUF_SIZE + RAW_BUF_SIZE)];
1099 
1100 	char *p = sym, *pend = sym + sizeof(sym);
1101 	int decode = (fmt[0] == 'R') ? 1 : 0;
1102 	const struct printf_spec *specp;
1103 
1104 	if (check_pointer(&buf, end, res, spec))
1105 		return buf;
1106 
1107 	*p++ = '[';
1108 	if (res->flags & IORESOURCE_IO) {
1109 		p = string_nocheck(p, pend, "io  ", str_spec);
1110 		specp = &io_spec;
1111 	} else if (res->flags & IORESOURCE_MEM) {
1112 		p = string_nocheck(p, pend, "mem ", str_spec);
1113 		specp = &mem_spec;
1114 	} else if (res->flags & IORESOURCE_IRQ) {
1115 		p = string_nocheck(p, pend, "irq ", str_spec);
1116 		specp = &default_dec_spec;
1117 	} else if (res->flags & IORESOURCE_DMA) {
1118 		p = string_nocheck(p, pend, "dma ", str_spec);
1119 		specp = &default_dec_spec;
1120 	} else if (res->flags & IORESOURCE_BUS) {
1121 		p = string_nocheck(p, pend, "bus ", str_spec);
1122 		specp = &bus_spec;
1123 	} else {
1124 		p = string_nocheck(p, pend, "??? ", str_spec);
1125 		specp = &mem_spec;
1126 		decode = 0;
1127 	}
1128 	if (decode && res->flags & IORESOURCE_UNSET) {
1129 		p = string_nocheck(p, pend, "size ", str_spec);
1130 		p = number(p, pend, resource_size(res), *specp);
1131 	} else {
1132 		p = hex_range(p, pend, res->start, res->end, *specp);
1133 	}
1134 	if (decode) {
1135 		if (res->flags & IORESOURCE_MEM_64)
1136 			p = string_nocheck(p, pend, " 64bit", str_spec);
1137 		if (res->flags & IORESOURCE_PREFETCH)
1138 			p = string_nocheck(p, pend, " pref", str_spec);
1139 		if (res->flags & IORESOURCE_WINDOW)
1140 			p = string_nocheck(p, pend, " window", str_spec);
1141 		if (res->flags & IORESOURCE_DISABLED)
1142 			p = string_nocheck(p, pend, " disabled", str_spec);
1143 	} else {
1144 		p = string_nocheck(p, pend, " flags ", str_spec);
1145 		p = number(p, pend, res->flags, default_flag_spec);
1146 	}
1147 	*p++ = ']';
1148 	*p = '\0';
1149 
1150 	return string_nocheck(buf, end, sym, spec);
1151 }
1152 
1153 static noinline_for_stack
1154 char *range_string(char *buf, char *end, const struct range *range,
1155 		   struct printf_spec spec, const char *fmt)
1156 {
1157 	char sym[sizeof("[range 0x0123456789abcdef-0x0123456789abcdef]")];
1158 	char *p = sym, *pend = sym + sizeof(sym);
1159 
1160 	struct printf_spec range_spec = {
1161 		.field_width = 2 + 2 * sizeof(range->start), /* 0x + 2 * 8 */
1162 		.flags = SPECIAL | SMALL | ZEROPAD,
1163 		.base = 16,
1164 		.precision = -1,
1165 	};
1166 
1167 	if (check_pointer(&buf, end, range, spec))
1168 		return buf;
1169 
1170 	p = string_nocheck(p, pend, "[range ", default_str_spec);
1171 	p = hex_range(p, pend, range->start, range->end, range_spec);
1172 	*p++ = ']';
1173 	*p = '\0';
1174 
1175 	return string_nocheck(buf, end, sym, spec);
1176 }
1177 
1178 static noinline_for_stack
1179 char *hex_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
1180 		 const char *fmt)
1181 {
1182 	int i, len = 1;		/* if we pass '%ph[CDN]', field width remains
1183 				   negative value, fallback to the default */
1184 	char separator;
1185 
1186 	if (spec.field_width == 0)
1187 		/* nothing to print */
1188 		return buf;
1189 
1190 	if (check_pointer(&buf, end, addr, spec))
1191 		return buf;
1192 
1193 	switch (fmt[1]) {
1194 	case 'C':
1195 		separator = ':';
1196 		break;
1197 	case 'D':
1198 		separator = '-';
1199 		break;
1200 	case 'N':
1201 		separator = 0;
1202 		break;
1203 	default:
1204 		separator = ' ';
1205 		break;
1206 	}
1207 
1208 	if (spec.field_width > 0)
1209 		len = min_t(int, spec.field_width, 64);
1210 
1211 	for (i = 0; i < len; ++i) {
1212 		if (buf < end)
1213 			*buf = hex_asc_hi(addr[i]);
1214 		++buf;
1215 		if (buf < end)
1216 			*buf = hex_asc_lo(addr[i]);
1217 		++buf;
1218 
1219 		if (separator && i != len - 1) {
1220 			if (buf < end)
1221 				*buf = separator;
1222 			++buf;
1223 		}
1224 	}
1225 
1226 	return buf;
1227 }
1228 
1229 static noinline_for_stack
1230 char *bitmap_string(char *buf, char *end, const unsigned long *bitmap,
1231 		    struct printf_spec spec, const char *fmt)
1232 {
1233 	const int CHUNKSZ = 32;
1234 	int nr_bits = max_t(int, spec.field_width, 0);
1235 	int i, chunksz;
1236 	bool first = true;
1237 
1238 	if (check_pointer(&buf, end, bitmap, spec))
1239 		return buf;
1240 
1241 	/* reused to print numbers */
1242 	spec = (struct printf_spec){ .flags = SMALL | ZEROPAD, .base = 16 };
1243 
1244 	chunksz = nr_bits & (CHUNKSZ - 1);
1245 	if (chunksz == 0)
1246 		chunksz = CHUNKSZ;
1247 
1248 	i = ALIGN(nr_bits, CHUNKSZ) - CHUNKSZ;
1249 	for (; i >= 0; i -= CHUNKSZ) {
1250 		u32 chunkmask, val;
1251 		int word, bit;
1252 
1253 		chunkmask = ((1ULL << chunksz) - 1);
1254 		word = i / BITS_PER_LONG;
1255 		bit = i % BITS_PER_LONG;
1256 		val = (bitmap[word] >> bit) & chunkmask;
1257 
1258 		if (!first) {
1259 			if (buf < end)
1260 				*buf = ',';
1261 			buf++;
1262 		}
1263 		first = false;
1264 
1265 		spec.field_width = DIV_ROUND_UP(chunksz, 4);
1266 		buf = number(buf, end, val, spec);
1267 
1268 		chunksz = CHUNKSZ;
1269 	}
1270 	return buf;
1271 }
1272 
1273 static noinline_for_stack
1274 char *bitmap_list_string(char *buf, char *end, const unsigned long *bitmap,
1275 			 struct printf_spec spec, const char *fmt)
1276 {
1277 	int nr_bits = max_t(int, spec.field_width, 0);
1278 	bool first = true;
1279 	int rbot, rtop;
1280 
1281 	if (check_pointer(&buf, end, bitmap, spec))
1282 		return buf;
1283 
1284 	for_each_set_bitrange(rbot, rtop, bitmap, nr_bits) {
1285 		if (!first) {
1286 			if (buf < end)
1287 				*buf = ',';
1288 			buf++;
1289 		}
1290 		first = false;
1291 
1292 		buf = number(buf, end, rbot, default_dec_spec);
1293 		if (rtop == rbot + 1)
1294 			continue;
1295 
1296 		if (buf < end)
1297 			*buf = '-';
1298 		buf = number(++buf, end, rtop - 1, default_dec_spec);
1299 	}
1300 	return buf;
1301 }
1302 
1303 static noinline_for_stack
1304 char *mac_address_string(char *buf, char *end, u8 *addr,
1305 			 struct printf_spec spec, const char *fmt)
1306 {
1307 	char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")];
1308 	char *p = mac_addr;
1309 	int i;
1310 	char separator;
1311 	bool reversed = false;
1312 
1313 	if (check_pointer(&buf, end, addr, spec))
1314 		return buf;
1315 
1316 	switch (fmt[1]) {
1317 	case 'F':
1318 		separator = '-';
1319 		break;
1320 
1321 	case 'R':
1322 		reversed = true;
1323 		fallthrough;
1324 
1325 	default:
1326 		separator = ':';
1327 		break;
1328 	}
1329 
1330 	for (i = 0; i < 6; i++) {
1331 		if (reversed)
1332 			p = hex_byte_pack(p, addr[5 - i]);
1333 		else
1334 			p = hex_byte_pack(p, addr[i]);
1335 
1336 		if (fmt[0] == 'M' && i != 5)
1337 			*p++ = separator;
1338 	}
1339 	*p = '\0';
1340 
1341 	return string_nocheck(buf, end, mac_addr, spec);
1342 }
1343 
1344 static noinline_for_stack
1345 char *ip4_string(char *p, const u8 *addr, const char *fmt)
1346 {
1347 	int i;
1348 	bool leading_zeros = (fmt[0] == 'i');
1349 	int index;
1350 	int step;
1351 
1352 	switch (fmt[2]) {
1353 	case 'h':
1354 #ifdef __BIG_ENDIAN
1355 		index = 0;
1356 		step = 1;
1357 #else
1358 		index = 3;
1359 		step = -1;
1360 #endif
1361 		break;
1362 	case 'l':
1363 		index = 3;
1364 		step = -1;
1365 		break;
1366 	case 'n':
1367 	case 'b':
1368 	default:
1369 		index = 0;
1370 		step = 1;
1371 		break;
1372 	}
1373 	for (i = 0; i < 4; i++) {
1374 		char temp[4] __aligned(2);	/* hold each IP quad in reverse order */
1375 		int digits = put_dec_trunc8(temp, addr[index]) - temp;
1376 		if (leading_zeros) {
1377 			if (digits < 3)
1378 				*p++ = '0';
1379 			if (digits < 2)
1380 				*p++ = '0';
1381 		}
1382 		/* reverse the digits in the quad */
1383 		while (digits--)
1384 			*p++ = temp[digits];
1385 		if (i < 3)
1386 			*p++ = '.';
1387 		index += step;
1388 	}
1389 	*p = '\0';
1390 
1391 	return p;
1392 }
1393 
1394 static noinline_for_stack
1395 char *ip6_compressed_string(char *p, const char *addr)
1396 {
1397 	int i, j, range;
1398 	unsigned char zerolength[8];
1399 	int longest = 1;
1400 	int colonpos = -1;
1401 	u16 word;
1402 	u8 hi, lo;
1403 	bool needcolon = false;
1404 	bool useIPv4;
1405 	struct in6_addr in6;
1406 
1407 	memcpy(&in6, addr, sizeof(struct in6_addr));
1408 
1409 	useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6);
1410 
1411 	memset(zerolength, 0, sizeof(zerolength));
1412 
1413 	if (useIPv4)
1414 		range = 6;
1415 	else
1416 		range = 8;
1417 
1418 	/* find position of longest 0 run */
1419 	for (i = 0; i < range; i++) {
1420 		for (j = i; j < range; j++) {
1421 			if (in6.s6_addr16[j] != 0)
1422 				break;
1423 			zerolength[i]++;
1424 		}
1425 	}
1426 	for (i = 0; i < range; i++) {
1427 		if (zerolength[i] > longest) {
1428 			longest = zerolength[i];
1429 			colonpos = i;
1430 		}
1431 	}
1432 	if (longest == 1)		/* don't compress a single 0 */
1433 		colonpos = -1;
1434 
1435 	/* emit address */
1436 	for (i = 0; i < range; i++) {
1437 		if (i == colonpos) {
1438 			if (needcolon || i == 0)
1439 				*p++ = ':';
1440 			*p++ = ':';
1441 			needcolon = false;
1442 			i += longest - 1;
1443 			continue;
1444 		}
1445 		if (needcolon) {
1446 			*p++ = ':';
1447 			needcolon = false;
1448 		}
1449 		/* hex u16 without leading 0s */
1450 		word = ntohs(in6.s6_addr16[i]);
1451 		hi = word >> 8;
1452 		lo = word & 0xff;
1453 		if (hi) {
1454 			if (hi > 0x0f)
1455 				p = hex_byte_pack(p, hi);
1456 			else
1457 				*p++ = hex_asc_lo(hi);
1458 			p = hex_byte_pack(p, lo);
1459 		}
1460 		else if (lo > 0x0f)
1461 			p = hex_byte_pack(p, lo);
1462 		else
1463 			*p++ = hex_asc_lo(lo);
1464 		needcolon = true;
1465 	}
1466 
1467 	if (useIPv4) {
1468 		if (needcolon)
1469 			*p++ = ':';
1470 		p = ip4_string(p, &in6.s6_addr[12], "I4");
1471 	}
1472 	*p = '\0';
1473 
1474 	return p;
1475 }
1476 
1477 static noinline_for_stack
1478 char *ip6_string(char *p, const char *addr, const char *fmt)
1479 {
1480 	int i;
1481 
1482 	for (i = 0; i < 8; i++) {
1483 		p = hex_byte_pack(p, *addr++);
1484 		p = hex_byte_pack(p, *addr++);
1485 		if (fmt[0] == 'I' && i != 7)
1486 			*p++ = ':';
1487 	}
1488 	*p = '\0';
1489 
1490 	return p;
1491 }
1492 
1493 static noinline_for_stack
1494 char *ip6_addr_string(char *buf, char *end, const u8 *addr,
1495 		      struct printf_spec spec, const char *fmt)
1496 {
1497 	char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")];
1498 
1499 	if (fmt[0] == 'I' && fmt[2] == 'c')
1500 		ip6_compressed_string(ip6_addr, addr);
1501 	else
1502 		ip6_string(ip6_addr, addr, fmt);
1503 
1504 	return string_nocheck(buf, end, ip6_addr, spec);
1505 }
1506 
1507 static noinline_for_stack
1508 char *ip4_addr_string(char *buf, char *end, const u8 *addr,
1509 		      struct printf_spec spec, const char *fmt)
1510 {
1511 	char ip4_addr[sizeof("255.255.255.255")];
1512 
1513 	ip4_string(ip4_addr, addr, fmt);
1514 
1515 	return string_nocheck(buf, end, ip4_addr, spec);
1516 }
1517 
1518 static noinline_for_stack
1519 char *ip6_addr_string_sa(char *buf, char *end, const struct sockaddr_in6 *sa,
1520 			 struct printf_spec spec, const char *fmt)
1521 {
1522 	bool have_p = false, have_s = false, have_f = false, have_c = false;
1523 	char ip6_addr[sizeof("[xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255]") +
1524 		      sizeof(":12345") + sizeof("/123456789") +
1525 		      sizeof("%1234567890")];
1526 	char *p = ip6_addr, *pend = ip6_addr + sizeof(ip6_addr);
1527 	const u8 *addr = (const u8 *) &sa->sin6_addr;
1528 	char fmt6[2] = { fmt[0], '6' };
1529 	u8 off = 0;
1530 
1531 	fmt++;
1532 	while (isalpha(*++fmt)) {
1533 		switch (*fmt) {
1534 		case 'p':
1535 			have_p = true;
1536 			break;
1537 		case 'f':
1538 			have_f = true;
1539 			break;
1540 		case 's':
1541 			have_s = true;
1542 			break;
1543 		case 'c':
1544 			have_c = true;
1545 			break;
1546 		}
1547 	}
1548 
1549 	if (have_p || have_s || have_f) {
1550 		*p = '[';
1551 		off = 1;
1552 	}
1553 
1554 	if (fmt6[0] == 'I' && have_c)
1555 		p = ip6_compressed_string(ip6_addr + off, addr);
1556 	else
1557 		p = ip6_string(ip6_addr + off, addr, fmt6);
1558 
1559 	if (have_p || have_s || have_f)
1560 		*p++ = ']';
1561 
1562 	if (have_p) {
1563 		*p++ = ':';
1564 		p = number(p, pend, ntohs(sa->sin6_port), spec);
1565 	}
1566 	if (have_f) {
1567 		*p++ = '/';
1568 		p = number(p, pend, ntohl(sa->sin6_flowinfo &
1569 					  IPV6_FLOWINFO_MASK), spec);
1570 	}
1571 	if (have_s) {
1572 		*p++ = '%';
1573 		p = number(p, pend, sa->sin6_scope_id, spec);
1574 	}
1575 	*p = '\0';
1576 
1577 	return string_nocheck(buf, end, ip6_addr, spec);
1578 }
1579 
1580 static noinline_for_stack
1581 char *ip4_addr_string_sa(char *buf, char *end, const struct sockaddr_in *sa,
1582 			 struct printf_spec spec, const char *fmt)
1583 {
1584 	bool have_p = false;
1585 	char *p, ip4_addr[sizeof("255.255.255.255") + sizeof(":12345")];
1586 	char *pend = ip4_addr + sizeof(ip4_addr);
1587 	const u8 *addr = (const u8 *) &sa->sin_addr.s_addr;
1588 	char fmt4[3] = { fmt[0], '4', 0 };
1589 
1590 	fmt++;
1591 	while (isalpha(*++fmt)) {
1592 		switch (*fmt) {
1593 		case 'p':
1594 			have_p = true;
1595 			break;
1596 		case 'h':
1597 		case 'l':
1598 		case 'n':
1599 		case 'b':
1600 			fmt4[2] = *fmt;
1601 			break;
1602 		}
1603 	}
1604 
1605 	p = ip4_string(ip4_addr, addr, fmt4);
1606 	if (have_p) {
1607 		*p++ = ':';
1608 		p = number(p, pend, ntohs(sa->sin_port), spec);
1609 	}
1610 	*p = '\0';
1611 
1612 	return string_nocheck(buf, end, ip4_addr, spec);
1613 }
1614 
1615 static noinline_for_stack
1616 char *ip_addr_string(char *buf, char *end, const void *ptr,
1617 		     struct printf_spec spec, const char *fmt)
1618 {
1619 	char *err_fmt_msg;
1620 
1621 	if (check_pointer(&buf, end, ptr, spec))
1622 		return buf;
1623 
1624 	switch (fmt[1]) {
1625 	case '6':
1626 		return ip6_addr_string(buf, end, ptr, spec, fmt);
1627 	case '4':
1628 		return ip4_addr_string(buf, end, ptr, spec, fmt);
1629 	case 'S': {
1630 		const union {
1631 			struct sockaddr		raw;
1632 			struct sockaddr_in	v4;
1633 			struct sockaddr_in6	v6;
1634 		} *sa = ptr;
1635 
1636 		switch (sa->raw.sa_family) {
1637 		case AF_INET:
1638 			return ip4_addr_string_sa(buf, end, &sa->v4, spec, fmt);
1639 		case AF_INET6:
1640 			return ip6_addr_string_sa(buf, end, &sa->v6, spec, fmt);
1641 		default:
1642 			return error_string(buf, end, "(einval)", spec);
1643 		}}
1644 	}
1645 
1646 	err_fmt_msg = fmt[0] == 'i' ? "(%pi?)" : "(%pI?)";
1647 	return error_string(buf, end, err_fmt_msg, spec);
1648 }
1649 
1650 static noinline_for_stack
1651 char *escaped_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
1652 		     const char *fmt)
1653 {
1654 	bool found = true;
1655 	int count = 1;
1656 	unsigned int flags = 0;
1657 	int len;
1658 
1659 	if (spec.field_width == 0)
1660 		return buf;				/* nothing to print */
1661 
1662 	if (check_pointer(&buf, end, addr, spec))
1663 		return buf;
1664 
1665 	do {
1666 		switch (fmt[count++]) {
1667 		case 'a':
1668 			flags |= ESCAPE_ANY;
1669 			break;
1670 		case 'c':
1671 			flags |= ESCAPE_SPECIAL;
1672 			break;
1673 		case 'h':
1674 			flags |= ESCAPE_HEX;
1675 			break;
1676 		case 'n':
1677 			flags |= ESCAPE_NULL;
1678 			break;
1679 		case 'o':
1680 			flags |= ESCAPE_OCTAL;
1681 			break;
1682 		case 'p':
1683 			flags |= ESCAPE_NP;
1684 			break;
1685 		case 's':
1686 			flags |= ESCAPE_SPACE;
1687 			break;
1688 		default:
1689 			found = false;
1690 			break;
1691 		}
1692 	} while (found);
1693 
1694 	if (!flags)
1695 		flags = ESCAPE_ANY_NP;
1696 
1697 	len = spec.field_width < 0 ? 1 : spec.field_width;
1698 
1699 	/*
1700 	 * string_escape_mem() writes as many characters as it can to
1701 	 * the given buffer, and returns the total size of the output
1702 	 * had the buffer been big enough.
1703 	 */
1704 	buf += string_escape_mem(addr, len, buf, buf < end ? end - buf : 0, flags, NULL);
1705 
1706 	return buf;
1707 }
1708 
1709 static char *va_format(char *buf, char *end, struct va_format *va_fmt,
1710 		       struct printf_spec spec, const char *fmt)
1711 {
1712 	va_list va;
1713 
1714 	if (check_pointer(&buf, end, va_fmt, spec))
1715 		return buf;
1716 
1717 	va_copy(va, *va_fmt->va);
1718 	buf += vsnprintf(buf, end > buf ? end - buf : 0, va_fmt->fmt, va);
1719 	va_end(va);
1720 
1721 	return buf;
1722 }
1723 
1724 static noinline_for_stack
1725 char *uuid_string(char *buf, char *end, const u8 *addr,
1726 		  struct printf_spec spec, const char *fmt)
1727 {
1728 	char uuid[UUID_STRING_LEN + 1];
1729 	char *p = uuid;
1730 	int i;
1731 	const u8 *index = uuid_index;
1732 	bool uc = false;
1733 
1734 	if (check_pointer(&buf, end, addr, spec))
1735 		return buf;
1736 
1737 	switch (*(++fmt)) {
1738 	case 'L':
1739 		uc = true;
1740 		fallthrough;
1741 	case 'l':
1742 		index = guid_index;
1743 		break;
1744 	case 'B':
1745 		uc = true;
1746 		break;
1747 	}
1748 
1749 	for (i = 0; i < 16; i++) {
1750 		if (uc)
1751 			p = hex_byte_pack_upper(p, addr[index[i]]);
1752 		else
1753 			p = hex_byte_pack(p, addr[index[i]]);
1754 		switch (i) {
1755 		case 3:
1756 		case 5:
1757 		case 7:
1758 		case 9:
1759 			*p++ = '-';
1760 			break;
1761 		}
1762 	}
1763 
1764 	*p = 0;
1765 
1766 	return string_nocheck(buf, end, uuid, spec);
1767 }
1768 
1769 static noinline_for_stack
1770 char *netdev_bits(char *buf, char *end, const void *addr,
1771 		  struct printf_spec spec,  const char *fmt)
1772 {
1773 	unsigned long long num;
1774 	int size;
1775 
1776 	if (check_pointer(&buf, end, addr, spec))
1777 		return buf;
1778 
1779 	switch (fmt[1]) {
1780 	case 'F':
1781 		num = *(const netdev_features_t *)addr;
1782 		size = sizeof(netdev_features_t);
1783 		break;
1784 	default:
1785 		return error_string(buf, end, "(%pN?)", spec);
1786 	}
1787 
1788 	return special_hex_number(buf, end, num, size);
1789 }
1790 
1791 static noinline_for_stack
1792 char *fourcc_string(char *buf, char *end, const u32 *fourcc,
1793 		    struct printf_spec spec, const char *fmt)
1794 {
1795 	char output[sizeof("0123 little-endian (0x01234567)")];
1796 	char *p = output;
1797 	unsigned int i;
1798 	u32 orig, val;
1799 
1800 	if (fmt[1] != 'c' || fmt[2] != 'c')
1801 		return error_string(buf, end, "(%p4?)", spec);
1802 
1803 	if (check_pointer(&buf, end, fourcc, spec))
1804 		return buf;
1805 
1806 	orig = get_unaligned(fourcc);
1807 	val = orig & ~BIT(31);
1808 
1809 	for (i = 0; i < sizeof(u32); i++) {
1810 		unsigned char c = val >> (i * 8);
1811 
1812 		/* Print non-control ASCII characters as-is, dot otherwise */
1813 		*p++ = isascii(c) && isprint(c) ? c : '.';
1814 	}
1815 
1816 	*p++ = ' ';
1817 	strcpy(p, orig & BIT(31) ? "big-endian" : "little-endian");
1818 	p += strlen(p);
1819 
1820 	*p++ = ' ';
1821 	*p++ = '(';
1822 	p = special_hex_number(p, output + sizeof(output) - 2, orig, sizeof(u32));
1823 	*p++ = ')';
1824 	*p = '\0';
1825 
1826 	return string(buf, end, output, spec);
1827 }
1828 
1829 static noinline_for_stack
1830 char *address_val(char *buf, char *end, const void *addr,
1831 		  struct printf_spec spec, const char *fmt)
1832 {
1833 	unsigned long long num;
1834 	int size;
1835 
1836 	if (check_pointer(&buf, end, addr, spec))
1837 		return buf;
1838 
1839 	switch (fmt[1]) {
1840 	case 'd':
1841 		num = *(const dma_addr_t *)addr;
1842 		size = sizeof(dma_addr_t);
1843 		break;
1844 	case 'p':
1845 	default:
1846 		num = *(const phys_addr_t *)addr;
1847 		size = sizeof(phys_addr_t);
1848 		break;
1849 	}
1850 
1851 	return special_hex_number(buf, end, num, size);
1852 }
1853 
1854 static noinline_for_stack
1855 char *date_str(char *buf, char *end, const struct rtc_time *tm, bool r)
1856 {
1857 	int year = tm->tm_year + (r ? 0 : 1900);
1858 	int mon = tm->tm_mon + (r ? 0 : 1);
1859 
1860 	buf = number(buf, end, year, default_dec04_spec);
1861 	if (buf < end)
1862 		*buf = '-';
1863 	buf++;
1864 
1865 	buf = number(buf, end, mon, default_dec02_spec);
1866 	if (buf < end)
1867 		*buf = '-';
1868 	buf++;
1869 
1870 	return number(buf, end, tm->tm_mday, default_dec02_spec);
1871 }
1872 
1873 static noinline_for_stack
1874 char *time_str(char *buf, char *end, const struct rtc_time *tm, bool r)
1875 {
1876 	buf = number(buf, end, tm->tm_hour, default_dec02_spec);
1877 	if (buf < end)
1878 		*buf = ':';
1879 	buf++;
1880 
1881 	buf = number(buf, end, tm->tm_min, default_dec02_spec);
1882 	if (buf < end)
1883 		*buf = ':';
1884 	buf++;
1885 
1886 	return number(buf, end, tm->tm_sec, default_dec02_spec);
1887 }
1888 
1889 static noinline_for_stack
1890 char *rtc_str(char *buf, char *end, const struct rtc_time *tm,
1891 	      struct printf_spec spec, const char *fmt)
1892 {
1893 	bool have_t = true, have_d = true;
1894 	bool raw = false, iso8601_separator = true;
1895 	bool found = true;
1896 	int count = 2;
1897 
1898 	if (check_pointer(&buf, end, tm, spec))
1899 		return buf;
1900 
1901 	switch (fmt[count]) {
1902 	case 'd':
1903 		have_t = false;
1904 		count++;
1905 		break;
1906 	case 't':
1907 		have_d = false;
1908 		count++;
1909 		break;
1910 	}
1911 
1912 	do {
1913 		switch (fmt[count++]) {
1914 		case 'r':
1915 			raw = true;
1916 			break;
1917 		case 's':
1918 			iso8601_separator = false;
1919 			break;
1920 		default:
1921 			found = false;
1922 			break;
1923 		}
1924 	} while (found);
1925 
1926 	if (have_d)
1927 		buf = date_str(buf, end, tm, raw);
1928 	if (have_d && have_t) {
1929 		if (buf < end)
1930 			*buf = iso8601_separator ? 'T' : ' ';
1931 		buf++;
1932 	}
1933 	if (have_t)
1934 		buf = time_str(buf, end, tm, raw);
1935 
1936 	return buf;
1937 }
1938 
1939 static noinline_for_stack
1940 char *time64_str(char *buf, char *end, const time64_t time,
1941 		 struct printf_spec spec, const char *fmt)
1942 {
1943 	struct rtc_time rtc_time;
1944 	struct tm tm;
1945 
1946 	time64_to_tm(time, 0, &tm);
1947 
1948 	rtc_time.tm_sec = tm.tm_sec;
1949 	rtc_time.tm_min = tm.tm_min;
1950 	rtc_time.tm_hour = tm.tm_hour;
1951 	rtc_time.tm_mday = tm.tm_mday;
1952 	rtc_time.tm_mon = tm.tm_mon;
1953 	rtc_time.tm_year = tm.tm_year;
1954 	rtc_time.tm_wday = tm.tm_wday;
1955 	rtc_time.tm_yday = tm.tm_yday;
1956 
1957 	rtc_time.tm_isdst = 0;
1958 
1959 	return rtc_str(buf, end, &rtc_time, spec, fmt);
1960 }
1961 
1962 static noinline_for_stack
1963 char *time_and_date(char *buf, char *end, void *ptr, struct printf_spec spec,
1964 		    const char *fmt)
1965 {
1966 	switch (fmt[1]) {
1967 	case 'R':
1968 		return rtc_str(buf, end, (const struct rtc_time *)ptr, spec, fmt);
1969 	case 'T':
1970 		return time64_str(buf, end, *(const time64_t *)ptr, spec, fmt);
1971 	default:
1972 		return error_string(buf, end, "(%pt?)", spec);
1973 	}
1974 }
1975 
1976 static noinline_for_stack
1977 char *clock(char *buf, char *end, struct clk *clk, struct printf_spec spec,
1978 	    const char *fmt)
1979 {
1980 	if (!IS_ENABLED(CONFIG_HAVE_CLK))
1981 		return error_string(buf, end, "(%pC?)", spec);
1982 
1983 	if (check_pointer(&buf, end, clk, spec))
1984 		return buf;
1985 
1986 	switch (fmt[1]) {
1987 	case 'n':
1988 	default:
1989 #ifdef CONFIG_COMMON_CLK
1990 		return string(buf, end, __clk_get_name(clk), spec);
1991 #else
1992 		return ptr_to_id(buf, end, clk, spec);
1993 #endif
1994 	}
1995 }
1996 
1997 static
1998 char *format_flags(char *buf, char *end, unsigned long flags,
1999 					const struct trace_print_flags *names)
2000 {
2001 	unsigned long mask;
2002 
2003 	for ( ; flags && names->name; names++) {
2004 		mask = names->mask;
2005 		if ((flags & mask) != mask)
2006 			continue;
2007 
2008 		buf = string(buf, end, names->name, default_str_spec);
2009 
2010 		flags &= ~mask;
2011 		if (flags) {
2012 			if (buf < end)
2013 				*buf = '|';
2014 			buf++;
2015 		}
2016 	}
2017 
2018 	if (flags)
2019 		buf = number(buf, end, flags, default_flag_spec);
2020 
2021 	return buf;
2022 }
2023 
2024 struct page_flags_fields {
2025 	int width;
2026 	int shift;
2027 	int mask;
2028 	const struct printf_spec *spec;
2029 	const char *name;
2030 };
2031 
2032 static const struct page_flags_fields pff[] = {
2033 	{SECTIONS_WIDTH, SECTIONS_PGSHIFT, SECTIONS_MASK,
2034 	 &default_dec_spec, "section"},
2035 	{NODES_WIDTH, NODES_PGSHIFT, NODES_MASK,
2036 	 &default_dec_spec, "node"},
2037 	{ZONES_WIDTH, ZONES_PGSHIFT, ZONES_MASK,
2038 	 &default_dec_spec, "zone"},
2039 	{LAST_CPUPID_WIDTH, LAST_CPUPID_PGSHIFT, LAST_CPUPID_MASK,
2040 	 &default_flag_spec, "lastcpupid"},
2041 	{KASAN_TAG_WIDTH, KASAN_TAG_PGSHIFT, KASAN_TAG_MASK,
2042 	 &default_flag_spec, "kasantag"},
2043 };
2044 
2045 static
2046 char *format_page_flags(char *buf, char *end, unsigned long flags)
2047 {
2048 	unsigned long main_flags = flags & PAGEFLAGS_MASK;
2049 	bool append = false;
2050 	int i;
2051 
2052 	buf = number(buf, end, flags, default_flag_spec);
2053 	if (buf < end)
2054 		*buf = '(';
2055 	buf++;
2056 
2057 	/* Page flags from the main area. */
2058 	if (main_flags) {
2059 		buf = format_flags(buf, end, main_flags, pageflag_names);
2060 		append = true;
2061 	}
2062 
2063 	/* Page flags from the fields area */
2064 	for (i = 0; i < ARRAY_SIZE(pff); i++) {
2065 		/* Skip undefined fields. */
2066 		if (!pff[i].width)
2067 			continue;
2068 
2069 		/* Format: Flag Name + '=' (equals sign) + Number + '|' (separator) */
2070 		if (append) {
2071 			if (buf < end)
2072 				*buf = '|';
2073 			buf++;
2074 		}
2075 
2076 		buf = string(buf, end, pff[i].name, default_str_spec);
2077 		if (buf < end)
2078 			*buf = '=';
2079 		buf++;
2080 		buf = number(buf, end, (flags >> pff[i].shift) & pff[i].mask,
2081 			     *pff[i].spec);
2082 
2083 		append = true;
2084 	}
2085 	if (buf < end)
2086 		*buf = ')';
2087 	buf++;
2088 
2089 	return buf;
2090 }
2091 
2092 static noinline_for_stack
2093 char *flags_string(char *buf, char *end, void *flags_ptr,
2094 		   struct printf_spec spec, const char *fmt)
2095 {
2096 	unsigned long flags;
2097 	const struct trace_print_flags *names;
2098 
2099 	if (check_pointer(&buf, end, flags_ptr, spec))
2100 		return buf;
2101 
2102 	switch (fmt[1]) {
2103 	case 'p':
2104 		return format_page_flags(buf, end, *(unsigned long *)flags_ptr);
2105 	case 'v':
2106 		flags = *(unsigned long *)flags_ptr;
2107 		names = vmaflag_names;
2108 		break;
2109 	case 'g':
2110 		flags = (__force unsigned long)(*(gfp_t *)flags_ptr);
2111 		names = gfpflag_names;
2112 		break;
2113 	default:
2114 		return error_string(buf, end, "(%pG?)", spec);
2115 	}
2116 
2117 	return format_flags(buf, end, flags, names);
2118 }
2119 
2120 static noinline_for_stack
2121 char *fwnode_full_name_string(struct fwnode_handle *fwnode, char *buf,
2122 			      char *end)
2123 {
2124 	int depth;
2125 
2126 	/* Loop starting from the root node to the current node. */
2127 	for (depth = fwnode_count_parents(fwnode); depth >= 0; depth--) {
2128 		/*
2129 		 * Only get a reference for other nodes (i.e. parent nodes).
2130 		 * fwnode refcount may be 0 here.
2131 		 */
2132 		struct fwnode_handle *__fwnode = depth ?
2133 			fwnode_get_nth_parent(fwnode, depth) : fwnode;
2134 
2135 		buf = string(buf, end, fwnode_get_name_prefix(__fwnode),
2136 			     default_str_spec);
2137 		buf = string(buf, end, fwnode_get_name(__fwnode),
2138 			     default_str_spec);
2139 
2140 		if (depth)
2141 			fwnode_handle_put(__fwnode);
2142 	}
2143 
2144 	return buf;
2145 }
2146 
2147 static noinline_for_stack
2148 char *device_node_string(char *buf, char *end, struct device_node *dn,
2149 			 struct printf_spec spec, const char *fmt)
2150 {
2151 	char tbuf[sizeof("xxxx") + 1];
2152 	const char *p;
2153 	int ret;
2154 	char *buf_start = buf;
2155 	struct property *prop;
2156 	bool has_mult, pass;
2157 
2158 	struct printf_spec str_spec = spec;
2159 	str_spec.field_width = -1;
2160 
2161 	if (fmt[0] != 'F')
2162 		return error_string(buf, end, "(%pO?)", spec);
2163 
2164 	if (!IS_ENABLED(CONFIG_OF))
2165 		return error_string(buf, end, "(%pOF?)", spec);
2166 
2167 	if (check_pointer(&buf, end, dn, spec))
2168 		return buf;
2169 
2170 	/* simple case without anything any more format specifiers */
2171 	fmt++;
2172 	if (fmt[0] == '\0' || strcspn(fmt,"fnpPFcC") > 0)
2173 		fmt = "f";
2174 
2175 	for (pass = false; strspn(fmt,"fnpPFcC"); fmt++, pass = true) {
2176 		int precision;
2177 		if (pass) {
2178 			if (buf < end)
2179 				*buf = ':';
2180 			buf++;
2181 		}
2182 
2183 		switch (*fmt) {
2184 		case 'f':	/* full_name */
2185 			buf = fwnode_full_name_string(of_fwnode_handle(dn), buf,
2186 						      end);
2187 			break;
2188 		case 'n':	/* name */
2189 			p = fwnode_get_name(of_fwnode_handle(dn));
2190 			precision = str_spec.precision;
2191 			str_spec.precision = strchrnul(p, '@') - p;
2192 			buf = string(buf, end, p, str_spec);
2193 			str_spec.precision = precision;
2194 			break;
2195 		case 'p':	/* phandle */
2196 			buf = number(buf, end, (unsigned int)dn->phandle, default_dec_spec);
2197 			break;
2198 		case 'P':	/* path-spec */
2199 			p = fwnode_get_name(of_fwnode_handle(dn));
2200 			if (!p[1])
2201 				p = "/";
2202 			buf = string(buf, end, p, str_spec);
2203 			break;
2204 		case 'F':	/* flags */
2205 			tbuf[0] = of_node_check_flag(dn, OF_DYNAMIC) ? 'D' : '-';
2206 			tbuf[1] = of_node_check_flag(dn, OF_DETACHED) ? 'd' : '-';
2207 			tbuf[2] = of_node_check_flag(dn, OF_POPULATED) ? 'P' : '-';
2208 			tbuf[3] = of_node_check_flag(dn, OF_POPULATED_BUS) ? 'B' : '-';
2209 			tbuf[4] = 0;
2210 			buf = string_nocheck(buf, end, tbuf, str_spec);
2211 			break;
2212 		case 'c':	/* major compatible string */
2213 			ret = of_property_read_string(dn, "compatible", &p);
2214 			if (!ret)
2215 				buf = string(buf, end, p, str_spec);
2216 			break;
2217 		case 'C':	/* full compatible string */
2218 			has_mult = false;
2219 			of_property_for_each_string(dn, "compatible", prop, p) {
2220 				if (has_mult)
2221 					buf = string_nocheck(buf, end, ",", str_spec);
2222 				buf = string_nocheck(buf, end, "\"", str_spec);
2223 				buf = string(buf, end, p, str_spec);
2224 				buf = string_nocheck(buf, end, "\"", str_spec);
2225 
2226 				has_mult = true;
2227 			}
2228 			break;
2229 		default:
2230 			break;
2231 		}
2232 	}
2233 
2234 	return widen_string(buf, buf - buf_start, end, spec);
2235 }
2236 
2237 static noinline_for_stack
2238 char *fwnode_string(char *buf, char *end, struct fwnode_handle *fwnode,
2239 		    struct printf_spec spec, const char *fmt)
2240 {
2241 	struct printf_spec str_spec = spec;
2242 	char *buf_start = buf;
2243 
2244 	str_spec.field_width = -1;
2245 
2246 	if (*fmt != 'w')
2247 		return error_string(buf, end, "(%pf?)", spec);
2248 
2249 	if (check_pointer(&buf, end, fwnode, spec))
2250 		return buf;
2251 
2252 	fmt++;
2253 
2254 	switch (*fmt) {
2255 	case 'P':	/* name */
2256 		buf = string(buf, end, fwnode_get_name(fwnode), str_spec);
2257 		break;
2258 	case 'f':	/* full_name */
2259 	default:
2260 		buf = fwnode_full_name_string(fwnode, buf, end);
2261 		break;
2262 	}
2263 
2264 	return widen_string(buf, buf - buf_start, end, spec);
2265 }
2266 
2267 static noinline_for_stack
2268 char *resource_or_range(const char *fmt, char *buf, char *end, void *ptr,
2269 			struct printf_spec spec)
2270 {
2271 	if (*fmt == 'r' && fmt[1] == 'a')
2272 		return range_string(buf, end, ptr, spec, fmt);
2273 	return resource_string(buf, end, ptr, spec, fmt);
2274 }
2275 
2276 int __init no_hash_pointers_enable(char *str)
2277 {
2278 	if (no_hash_pointers)
2279 		return 0;
2280 
2281 	no_hash_pointers = true;
2282 
2283 	pr_warn("**********************************************************\n");
2284 	pr_warn("**   NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE   **\n");
2285 	pr_warn("**                                                      **\n");
2286 	pr_warn("** This system shows unhashed kernel memory addresses   **\n");
2287 	pr_warn("** via the console, logs, and other interfaces. This    **\n");
2288 	pr_warn("** might reduce the security of your system.            **\n");
2289 	pr_warn("**                                                      **\n");
2290 	pr_warn("** If you see this message and you are not debugging    **\n");
2291 	pr_warn("** the kernel, report this immediately to your system   **\n");
2292 	pr_warn("** administrator!                                       **\n");
2293 	pr_warn("**                                                      **\n");
2294 	pr_warn("**   NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE   **\n");
2295 	pr_warn("**********************************************************\n");
2296 
2297 	return 0;
2298 }
2299 early_param("no_hash_pointers", no_hash_pointers_enable);
2300 
2301 /* Used for Rust formatting ('%pA'). */
2302 char *rust_fmt_argument(char *buf, char *end, void *ptr);
2303 
2304 /*
2305  * Show a '%p' thing.  A kernel extension is that the '%p' is followed
2306  * by an extra set of alphanumeric characters that are extended format
2307  * specifiers.
2308  *
2309  * Please update scripts/checkpatch.pl when adding/removing conversion
2310  * characters.  (Search for "check for vsprintf extension").
2311  *
2312  * Right now we handle:
2313  *
2314  * - 'S' For symbolic direct pointers (or function descriptors) with offset
2315  * - 's' For symbolic direct pointers (or function descriptors) without offset
2316  * - '[Ss]R' as above with __builtin_extract_return_addr() translation
2317  * - 'S[R]b' as above with module build ID (for use in backtraces)
2318  * - '[Ff]' %pf and %pF were obsoleted and later removed in favor of
2319  *	    %ps and %pS. Be careful when re-using these specifiers.
2320  * - 'B' For backtraced symbolic direct pointers with offset
2321  * - 'Bb' as above with module build ID (for use in backtraces)
2322  * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref]
2323  * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201]
2324  * - 'ra' For struct ranges, e.g., [range 0x0000000000000000 - 0x00000000000000ff]
2325  * - 'b[l]' For a bitmap, the number of bits is determined by the field
2326  *       width which must be explicitly specified either as part of the
2327  *       format string '%32b[l]' or through '%*b[l]', [l] selects
2328  *       range-list format instead of hex format
2329  * - 'M' For a 6-byte MAC address, it prints the address in the
2330  *       usual colon-separated hex notation
2331  * - 'm' For a 6-byte MAC address, it prints the hex address without colons
2332  * - 'MF' For a 6-byte MAC FDDI address, it prints the address
2333  *       with a dash-separated hex notation
2334  * - '[mM]R' For a 6-byte MAC address, Reverse order (Bluetooth)
2335  * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way
2336  *       IPv4 uses dot-separated decimal without leading 0's (1.2.3.4)
2337  *       IPv6 uses colon separated network-order 16 bit hex with leading 0's
2338  *       [S][pfs]
2339  *       Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
2340  *       [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
2341  * - 'i' [46] for 'raw' IPv4/IPv6 addresses
2342  *       IPv6 omits the colons (01020304...0f)
2343  *       IPv4 uses dot-separated decimal with leading 0's (010.123.045.006)
2344  *       [S][pfs]
2345  *       Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
2346  *       [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
2347  * - '[Ii][4S][hnbl]' IPv4 addresses in host, network, big or little endian order
2348  * - 'I[6S]c' for IPv6 addresses printed as specified by
2349  *       https://tools.ietf.org/html/rfc5952
2350  * - 'E[achnops]' For an escaped buffer, where rules are defined by combination
2351  *                of the following flags (see string_escape_mem() for the
2352  *                details):
2353  *                  a - ESCAPE_ANY
2354  *                  c - ESCAPE_SPECIAL
2355  *                  h - ESCAPE_HEX
2356  *                  n - ESCAPE_NULL
2357  *                  o - ESCAPE_OCTAL
2358  *                  p - ESCAPE_NP
2359  *                  s - ESCAPE_SPACE
2360  *                By default ESCAPE_ANY_NP is used.
2361  * - 'U' For a 16 byte UUID/GUID, it prints the UUID/GUID in the form
2362  *       "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
2363  *       Options for %pU are:
2364  *         b big endian lower case hex (default)
2365  *         B big endian UPPER case hex
2366  *         l little endian lower case hex
2367  *         L little endian UPPER case hex
2368  *           big endian output byte order is:
2369  *             [0][1][2][3]-[4][5]-[6][7]-[8][9]-[10][11][12][13][14][15]
2370  *           little endian output byte order is:
2371  *             [3][2][1][0]-[5][4]-[7][6]-[8][9]-[10][11][12][13][14][15]
2372  * - 'V' For a struct va_format which contains a format string * and va_list *,
2373  *       call vsnprintf(->format, *->va_list).
2374  *       Implements a "recursive vsnprintf".
2375  *       Do not use this feature without some mechanism to verify the
2376  *       correctness of the format string and va_list arguments.
2377  * - 'K' For a kernel pointer that should be hidden from unprivileged users.
2378  *       Use only for procfs, sysfs and similar files, not printk(); please
2379  *       read the documentation (path below) first.
2380  * - 'NF' For a netdev_features_t
2381  * - '4cc' V4L2 or DRM FourCC code, with endianness and raw numerical value.
2382  * - 'h[CDN]' For a variable-length buffer, it prints it as a hex string with
2383  *            a certain separator (' ' by default):
2384  *              C colon
2385  *              D dash
2386  *              N no separator
2387  *            The maximum supported length is 64 bytes of the input. Consider
2388  *            to use print_hex_dump() for the larger input.
2389  * - 'a[pd]' For address types [p] phys_addr_t, [d] dma_addr_t and derivatives
2390  *           (default assumed to be phys_addr_t, passed by reference)
2391  * - 'd[234]' For a dentry name (optionally 2-4 last components)
2392  * - 'D[234]' Same as 'd' but for a struct file
2393  * - 'g' For block_device name (gendisk + partition number)
2394  * - 't[RT][dt][r][s]' For time and date as represented by:
2395  *      R    struct rtc_time
2396  *      T    time64_t
2397  * - 'C' For a clock, it prints the name (Common Clock Framework) or address
2398  *       (legacy clock framework) of the clock
2399  * - 'Cn' For a clock, it prints the name (Common Clock Framework) or address
2400  *        (legacy clock framework) of the clock
2401  * - 'G' For flags to be printed as a collection of symbolic strings that would
2402  *       construct the specific value. Supported flags given by option:
2403  *       p page flags (see struct page) given as pointer to unsigned long
2404  *       g gfp flags (GFP_* and __GFP_*) given as pointer to gfp_t
2405  *       v vma flags (VM_*) given as pointer to unsigned long
2406  * - 'OF[fnpPcCF]'  For a device tree object
2407  *                  Without any optional arguments prints the full_name
2408  *                  f device node full_name
2409  *                  n device node name
2410  *                  p device node phandle
2411  *                  P device node path spec (name + @unit)
2412  *                  F device node flags
2413  *                  c major compatible string
2414  *                  C full compatible string
2415  * - 'fw[fP]'	For a firmware node (struct fwnode_handle) pointer
2416  *		Without an option prints the full name of the node
2417  *		f full name
2418  *		P node name, including a possible unit address
2419  * - 'x' For printing the address unmodified. Equivalent to "%lx".
2420  *       Please read the documentation (path below) before using!
2421  * - '[ku]s' For a BPF/tracing related format specifier, e.g. used out of
2422  *           bpf_trace_printk() where [ku] prefix specifies either kernel (k)
2423  *           or user (u) memory to probe, and:
2424  *              s a string, equivalent to "%s" on direct vsnprintf() use
2425  *
2426  * ** When making changes please also update:
2427  *	Documentation/core-api/printk-formats.rst
2428  *
2429  * Note: The default behaviour (unadorned %p) is to hash the address,
2430  * rendering it useful as a unique identifier.
2431  *
2432  * There is also a '%pA' format specifier, but it is only intended to be used
2433  * from Rust code to format core::fmt::Arguments. Do *not* use it from C.
2434  * See rust/kernel/print.rs for details.
2435  */
2436 static noinline_for_stack
2437 char *pointer(const char *fmt, char *buf, char *end, void *ptr,
2438 	      struct printf_spec spec)
2439 {
2440 	switch (*fmt) {
2441 	case 'S':
2442 	case 's':
2443 		ptr = dereference_symbol_descriptor(ptr);
2444 		fallthrough;
2445 	case 'B':
2446 		return symbol_string(buf, end, ptr, spec, fmt);
2447 	case 'R':
2448 	case 'r':
2449 		return resource_or_range(fmt, buf, end, ptr, spec);
2450 	case 'h':
2451 		return hex_string(buf, end, ptr, spec, fmt);
2452 	case 'b':
2453 		switch (fmt[1]) {
2454 		case 'l':
2455 			return bitmap_list_string(buf, end, ptr, spec, fmt);
2456 		default:
2457 			return bitmap_string(buf, end, ptr, spec, fmt);
2458 		}
2459 	case 'M':			/* Colon separated: 00:01:02:03:04:05 */
2460 	case 'm':			/* Contiguous: 000102030405 */
2461 					/* [mM]F (FDDI) */
2462 					/* [mM]R (Reverse order; Bluetooth) */
2463 		return mac_address_string(buf, end, ptr, spec, fmt);
2464 	case 'I':			/* Formatted IP supported
2465 					 * 4:	1.2.3.4
2466 					 * 6:	0001:0203:...:0708
2467 					 * 6c:	1::708 or 1::1.2.3.4
2468 					 */
2469 	case 'i':			/* Contiguous:
2470 					 * 4:	001.002.003.004
2471 					 * 6:   000102...0f
2472 					 */
2473 		return ip_addr_string(buf, end, ptr, spec, fmt);
2474 	case 'E':
2475 		return escaped_string(buf, end, ptr, spec, fmt);
2476 	case 'U':
2477 		return uuid_string(buf, end, ptr, spec, fmt);
2478 	case 'V':
2479 		return va_format(buf, end, ptr, spec, fmt);
2480 	case 'K':
2481 		return restricted_pointer(buf, end, ptr, spec);
2482 	case 'N':
2483 		return netdev_bits(buf, end, ptr, spec, fmt);
2484 	case '4':
2485 		return fourcc_string(buf, end, ptr, spec, fmt);
2486 	case 'a':
2487 		return address_val(buf, end, ptr, spec, fmt);
2488 	case 'd':
2489 		return dentry_name(buf, end, ptr, spec, fmt);
2490 	case 't':
2491 		return time_and_date(buf, end, ptr, spec, fmt);
2492 	case 'C':
2493 		return clock(buf, end, ptr, spec, fmt);
2494 	case 'D':
2495 		return file_dentry_name(buf, end, ptr, spec, fmt);
2496 #ifdef CONFIG_BLOCK
2497 	case 'g':
2498 		return bdev_name(buf, end, ptr, spec, fmt);
2499 #endif
2500 
2501 	case 'G':
2502 		return flags_string(buf, end, ptr, spec, fmt);
2503 	case 'O':
2504 		return device_node_string(buf, end, ptr, spec, fmt + 1);
2505 	case 'f':
2506 		return fwnode_string(buf, end, ptr, spec, fmt + 1);
2507 	case 'A':
2508 		if (!IS_ENABLED(CONFIG_RUST)) {
2509 			WARN_ONCE(1, "Please remove %%pA from non-Rust code\n");
2510 			return error_string(buf, end, "(%pA?)", spec);
2511 		}
2512 		return rust_fmt_argument(buf, end, ptr);
2513 	case 'x':
2514 		return pointer_string(buf, end, ptr, spec);
2515 	case 'e':
2516 		/* %pe with a non-ERR_PTR gets treated as plain %p */
2517 		if (!IS_ERR(ptr))
2518 			return default_pointer(buf, end, ptr, spec);
2519 		return err_ptr(buf, end, ptr, spec);
2520 	case 'u':
2521 	case 'k':
2522 		switch (fmt[1]) {
2523 		case 's':
2524 			return string(buf, end, ptr, spec);
2525 		default:
2526 			return error_string(buf, end, "(einval)", spec);
2527 		}
2528 	default:
2529 		return default_pointer(buf, end, ptr, spec);
2530 	}
2531 }
2532 
2533 /*
2534  * Helper function to decode printf style format.
2535  * Each call decode a token from the format and return the
2536  * number of characters read (or likely the delta where it wants
2537  * to go on the next call).
2538  * The decoded token is returned through the parameters
2539  *
2540  * 'h', 'l', or 'L' for integer fields
2541  * 'z' support added 23/7/1999 S.H.
2542  * 'z' changed to 'Z' --davidm 1/25/99
2543  * 'Z' changed to 'z' --adobriyan 2017-01-25
2544  * 't' added for ptrdiff_t
2545  *
2546  * @fmt: the format string
2547  * @type of the token returned
2548  * @flags: various flags such as +, -, # tokens..
2549  * @field_width: overwritten width
2550  * @base: base of the number (octal, hex, ...)
2551  * @precision: precision of a number
2552  * @qualifier: qualifier of a number (long, size_t, ...)
2553  */
2554 static noinline_for_stack
2555 int format_decode(const char *fmt, struct printf_spec *spec)
2556 {
2557 	const char *start = fmt;
2558 	char qualifier;
2559 
2560 	/* we finished early by reading the field width */
2561 	if (spec->type == FORMAT_TYPE_WIDTH) {
2562 		if (spec->field_width < 0) {
2563 			spec->field_width = -spec->field_width;
2564 			spec->flags |= LEFT;
2565 		}
2566 		spec->type = FORMAT_TYPE_NONE;
2567 		goto precision;
2568 	}
2569 
2570 	/* we finished early by reading the precision */
2571 	if (spec->type == FORMAT_TYPE_PRECISION) {
2572 		if (spec->precision < 0)
2573 			spec->precision = 0;
2574 
2575 		spec->type = FORMAT_TYPE_NONE;
2576 		goto qualifier;
2577 	}
2578 
2579 	/* By default */
2580 	spec->type = FORMAT_TYPE_NONE;
2581 
2582 	for (; *fmt ; ++fmt) {
2583 		if (*fmt == '%')
2584 			break;
2585 	}
2586 
2587 	/* Return the current non-format string */
2588 	if (fmt != start || !*fmt)
2589 		return fmt - start;
2590 
2591 	/* Process flags */
2592 	spec->flags = 0;
2593 
2594 	while (1) { /* this also skips first '%' */
2595 		bool found = true;
2596 
2597 		++fmt;
2598 
2599 		switch (*fmt) {
2600 		case '-': spec->flags |= LEFT;    break;
2601 		case '+': spec->flags |= PLUS;    break;
2602 		case ' ': spec->flags |= SPACE;   break;
2603 		case '#': spec->flags |= SPECIAL; break;
2604 		case '0': spec->flags |= ZEROPAD; break;
2605 		default:  found = false;
2606 		}
2607 
2608 		if (!found)
2609 			break;
2610 	}
2611 
2612 	/* get field width */
2613 	spec->field_width = -1;
2614 
2615 	if (isdigit(*fmt))
2616 		spec->field_width = skip_atoi(&fmt);
2617 	else if (*fmt == '*') {
2618 		/* it's the next argument */
2619 		spec->type = FORMAT_TYPE_WIDTH;
2620 		return ++fmt - start;
2621 	}
2622 
2623 precision:
2624 	/* get the precision */
2625 	spec->precision = -1;
2626 	if (*fmt == '.') {
2627 		++fmt;
2628 		if (isdigit(*fmt)) {
2629 			spec->precision = skip_atoi(&fmt);
2630 			if (spec->precision < 0)
2631 				spec->precision = 0;
2632 		} else if (*fmt == '*') {
2633 			/* it's the next argument */
2634 			spec->type = FORMAT_TYPE_PRECISION;
2635 			return ++fmt - start;
2636 		}
2637 	}
2638 
2639 qualifier:
2640 	/* get the conversion qualifier */
2641 	qualifier = 0;
2642 	if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
2643 	    *fmt == 'z' || *fmt == 't') {
2644 		qualifier = *fmt++;
2645 		if (unlikely(qualifier == *fmt)) {
2646 			if (qualifier == 'l') {
2647 				qualifier = 'L';
2648 				++fmt;
2649 			} else if (qualifier == 'h') {
2650 				qualifier = 'H';
2651 				++fmt;
2652 			}
2653 		}
2654 	}
2655 
2656 	/* default base */
2657 	spec->base = 10;
2658 	switch (*fmt) {
2659 	case 'c':
2660 		spec->type = FORMAT_TYPE_CHAR;
2661 		return ++fmt - start;
2662 
2663 	case 's':
2664 		spec->type = FORMAT_TYPE_STR;
2665 		return ++fmt - start;
2666 
2667 	case 'p':
2668 		spec->type = FORMAT_TYPE_PTR;
2669 		return ++fmt - start;
2670 
2671 	case '%':
2672 		spec->type = FORMAT_TYPE_PERCENT_CHAR;
2673 		return ++fmt - start;
2674 
2675 	/* integer number formats - set up the flags and "break" */
2676 	case 'o':
2677 		spec->base = 8;
2678 		break;
2679 
2680 	case 'x':
2681 		spec->flags |= SMALL;
2682 		fallthrough;
2683 
2684 	case 'X':
2685 		spec->base = 16;
2686 		break;
2687 
2688 	case 'd':
2689 	case 'i':
2690 		spec->flags |= SIGN;
2691 		break;
2692 	case 'u':
2693 		break;
2694 
2695 	case 'n':
2696 		/*
2697 		 * Since %n poses a greater security risk than
2698 		 * utility, treat it as any other invalid or
2699 		 * unsupported format specifier.
2700 		 */
2701 		fallthrough;
2702 
2703 	default:
2704 		WARN_ONCE(1, "Please remove unsupported %%%c in format string\n", *fmt);
2705 		spec->type = FORMAT_TYPE_INVALID;
2706 		return fmt - start;
2707 	}
2708 
2709 	if (qualifier == 'L')
2710 		spec->type = FORMAT_TYPE_LONG_LONG;
2711 	else if (qualifier == 'l') {
2712 		BUILD_BUG_ON(FORMAT_TYPE_ULONG + SIGN != FORMAT_TYPE_LONG);
2713 		spec->type = FORMAT_TYPE_ULONG + (spec->flags & SIGN);
2714 	} else if (qualifier == 'z') {
2715 		spec->type = FORMAT_TYPE_SIZE_T;
2716 	} else if (qualifier == 't') {
2717 		spec->type = FORMAT_TYPE_PTRDIFF;
2718 	} else if (qualifier == 'H') {
2719 		BUILD_BUG_ON(FORMAT_TYPE_UBYTE + SIGN != FORMAT_TYPE_BYTE);
2720 		spec->type = FORMAT_TYPE_UBYTE + (spec->flags & SIGN);
2721 	} else if (qualifier == 'h') {
2722 		BUILD_BUG_ON(FORMAT_TYPE_USHORT + SIGN != FORMAT_TYPE_SHORT);
2723 		spec->type = FORMAT_TYPE_USHORT + (spec->flags & SIGN);
2724 	} else {
2725 		BUILD_BUG_ON(FORMAT_TYPE_UINT + SIGN != FORMAT_TYPE_INT);
2726 		spec->type = FORMAT_TYPE_UINT + (spec->flags & SIGN);
2727 	}
2728 
2729 	return ++fmt - start;
2730 }
2731 
2732 static void
2733 set_field_width(struct printf_spec *spec, int width)
2734 {
2735 	spec->field_width = width;
2736 	if (WARN_ONCE(spec->field_width != width, "field width %d too large", width)) {
2737 		spec->field_width = clamp(width, -FIELD_WIDTH_MAX, FIELD_WIDTH_MAX);
2738 	}
2739 }
2740 
2741 static void
2742 set_precision(struct printf_spec *spec, int prec)
2743 {
2744 	spec->precision = prec;
2745 	if (WARN_ONCE(spec->precision != prec, "precision %d too large", prec)) {
2746 		spec->precision = clamp(prec, 0, PRECISION_MAX);
2747 	}
2748 }
2749 
2750 /**
2751  * vsnprintf - Format a string and place it in a buffer
2752  * @buf: The buffer to place the result into
2753  * @size: The size of the buffer, including the trailing null space
2754  * @fmt: The format string to use
2755  * @args: Arguments for the format string
2756  *
2757  * This function generally follows C99 vsnprintf, but has some
2758  * extensions and a few limitations:
2759  *
2760  *  - ``%n`` is unsupported
2761  *  - ``%p*`` is handled by pointer()
2762  *
2763  * See pointer() or Documentation/core-api/printk-formats.rst for more
2764  * extensive description.
2765  *
2766  * **Please update the documentation in both places when making changes**
2767  *
2768  * The return value is the number of characters which would
2769  * be generated for the given input, excluding the trailing
2770  * '\0', as per ISO C99. If you want to have the exact
2771  * number of characters written into @buf as return value
2772  * (not including the trailing '\0'), use vscnprintf(). If the
2773  * return is greater than or equal to @size, the resulting
2774  * string is truncated.
2775  *
2776  * If you're not already dealing with a va_list consider using snprintf().
2777  */
2778 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
2779 {
2780 	unsigned long long num;
2781 	char *str, *end;
2782 	struct printf_spec spec = {0};
2783 
2784 	/* Reject out-of-range values early.  Large positive sizes are
2785 	   used for unknown buffer sizes. */
2786 	if (WARN_ON_ONCE(size > INT_MAX))
2787 		return 0;
2788 
2789 	str = buf;
2790 	end = buf + size;
2791 
2792 	/* Make sure end is always >= buf */
2793 	if (end < buf) {
2794 		end = ((void *)-1);
2795 		size = end - buf;
2796 	}
2797 
2798 	while (*fmt) {
2799 		const char *old_fmt = fmt;
2800 		int read = format_decode(fmt, &spec);
2801 
2802 		fmt += read;
2803 
2804 		switch (spec.type) {
2805 		case FORMAT_TYPE_NONE: {
2806 			int copy = read;
2807 			if (str < end) {
2808 				if (copy > end - str)
2809 					copy = end - str;
2810 				memcpy(str, old_fmt, copy);
2811 			}
2812 			str += read;
2813 			break;
2814 		}
2815 
2816 		case FORMAT_TYPE_WIDTH:
2817 			set_field_width(&spec, va_arg(args, int));
2818 			break;
2819 
2820 		case FORMAT_TYPE_PRECISION:
2821 			set_precision(&spec, va_arg(args, int));
2822 			break;
2823 
2824 		case FORMAT_TYPE_CHAR: {
2825 			char c;
2826 
2827 			if (!(spec.flags & LEFT)) {
2828 				while (--spec.field_width > 0) {
2829 					if (str < end)
2830 						*str = ' ';
2831 					++str;
2832 
2833 				}
2834 			}
2835 			c = (unsigned char) va_arg(args, int);
2836 			if (str < end)
2837 				*str = c;
2838 			++str;
2839 			while (--spec.field_width > 0) {
2840 				if (str < end)
2841 					*str = ' ';
2842 				++str;
2843 			}
2844 			break;
2845 		}
2846 
2847 		case FORMAT_TYPE_STR:
2848 			str = string(str, end, va_arg(args, char *), spec);
2849 			break;
2850 
2851 		case FORMAT_TYPE_PTR:
2852 			str = pointer(fmt, str, end, va_arg(args, void *),
2853 				      spec);
2854 			while (isalnum(*fmt))
2855 				fmt++;
2856 			break;
2857 
2858 		case FORMAT_TYPE_PERCENT_CHAR:
2859 			if (str < end)
2860 				*str = '%';
2861 			++str;
2862 			break;
2863 
2864 		case FORMAT_TYPE_INVALID:
2865 			/*
2866 			 * Presumably the arguments passed gcc's type
2867 			 * checking, but there is no safe or sane way
2868 			 * for us to continue parsing the format and
2869 			 * fetching from the va_list; the remaining
2870 			 * specifiers and arguments would be out of
2871 			 * sync.
2872 			 */
2873 			goto out;
2874 
2875 		default:
2876 			switch (spec.type) {
2877 			case FORMAT_TYPE_LONG_LONG:
2878 				num = va_arg(args, long long);
2879 				break;
2880 			case FORMAT_TYPE_ULONG:
2881 				num = va_arg(args, unsigned long);
2882 				break;
2883 			case FORMAT_TYPE_LONG:
2884 				num = va_arg(args, long);
2885 				break;
2886 			case FORMAT_TYPE_SIZE_T:
2887 				if (spec.flags & SIGN)
2888 					num = va_arg(args, ssize_t);
2889 				else
2890 					num = va_arg(args, size_t);
2891 				break;
2892 			case FORMAT_TYPE_PTRDIFF:
2893 				num = va_arg(args, ptrdiff_t);
2894 				break;
2895 			case FORMAT_TYPE_UBYTE:
2896 				num = (unsigned char) va_arg(args, int);
2897 				break;
2898 			case FORMAT_TYPE_BYTE:
2899 				num = (signed char) va_arg(args, int);
2900 				break;
2901 			case FORMAT_TYPE_USHORT:
2902 				num = (unsigned short) va_arg(args, int);
2903 				break;
2904 			case FORMAT_TYPE_SHORT:
2905 				num = (short) va_arg(args, int);
2906 				break;
2907 			case FORMAT_TYPE_INT:
2908 				num = (int) va_arg(args, int);
2909 				break;
2910 			default:
2911 				num = va_arg(args, unsigned int);
2912 			}
2913 
2914 			str = number(str, end, num, spec);
2915 		}
2916 	}
2917 
2918 out:
2919 	if (size > 0) {
2920 		if (str < end)
2921 			*str = '\0';
2922 		else
2923 			end[-1] = '\0';
2924 	}
2925 
2926 	/* the trailing null byte doesn't count towards the total */
2927 	return str-buf;
2928 
2929 }
2930 EXPORT_SYMBOL(vsnprintf);
2931 
2932 /**
2933  * vscnprintf - Format a string and place it in a buffer
2934  * @buf: The buffer to place the result into
2935  * @size: The size of the buffer, including the trailing null space
2936  * @fmt: The format string to use
2937  * @args: Arguments for the format string
2938  *
2939  * The return value is the number of characters which have been written into
2940  * the @buf not including the trailing '\0'. If @size is == 0 the function
2941  * returns 0.
2942  *
2943  * If you're not already dealing with a va_list consider using scnprintf().
2944  *
2945  * See the vsnprintf() documentation for format string extensions over C99.
2946  */
2947 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
2948 {
2949 	int i;
2950 
2951 	if (unlikely(!size))
2952 		return 0;
2953 
2954 	i = vsnprintf(buf, size, fmt, args);
2955 
2956 	if (likely(i < size))
2957 		return i;
2958 
2959 	return size - 1;
2960 }
2961 EXPORT_SYMBOL(vscnprintf);
2962 
2963 /**
2964  * snprintf - Format a string and place it in a buffer
2965  * @buf: The buffer to place the result into
2966  * @size: The size of the buffer, including the trailing null space
2967  * @fmt: The format string to use
2968  * @...: Arguments for the format string
2969  *
2970  * The return value is the number of characters which would be
2971  * generated for the given input, excluding the trailing null,
2972  * as per ISO C99.  If the return is greater than or equal to
2973  * @size, the resulting string is truncated.
2974  *
2975  * See the vsnprintf() documentation for format string extensions over C99.
2976  */
2977 int snprintf(char *buf, size_t size, const char *fmt, ...)
2978 {
2979 	va_list args;
2980 	int i;
2981 
2982 	va_start(args, fmt);
2983 	i = vsnprintf(buf, size, fmt, args);
2984 	va_end(args);
2985 
2986 	return i;
2987 }
2988 EXPORT_SYMBOL(snprintf);
2989 
2990 /**
2991  * scnprintf - Format a string and place it in a buffer
2992  * @buf: The buffer to place the result into
2993  * @size: The size of the buffer, including the trailing null space
2994  * @fmt: The format string to use
2995  * @...: Arguments for the format string
2996  *
2997  * The return value is the number of characters written into @buf not including
2998  * the trailing '\0'. If @size is == 0 the function returns 0.
2999  */
3000 
3001 int scnprintf(char *buf, size_t size, const char *fmt, ...)
3002 {
3003 	va_list args;
3004 	int i;
3005 
3006 	va_start(args, fmt);
3007 	i = vscnprintf(buf, size, fmt, args);
3008 	va_end(args);
3009 
3010 	return i;
3011 }
3012 EXPORT_SYMBOL(scnprintf);
3013 
3014 /**
3015  * vsprintf - Format a string and place it in a buffer
3016  * @buf: The buffer to place the result into
3017  * @fmt: The format string to use
3018  * @args: Arguments for the format string
3019  *
3020  * The function returns the number of characters written
3021  * into @buf. Use vsnprintf() or vscnprintf() in order to avoid
3022  * buffer overflows.
3023  *
3024  * If you're not already dealing with a va_list consider using sprintf().
3025  *
3026  * See the vsnprintf() documentation for format string extensions over C99.
3027  */
3028 int vsprintf(char *buf, const char *fmt, va_list args)
3029 {
3030 	return vsnprintf(buf, INT_MAX, fmt, args);
3031 }
3032 EXPORT_SYMBOL(vsprintf);
3033 
3034 /**
3035  * sprintf - Format a string and place it in a buffer
3036  * @buf: The buffer to place the result into
3037  * @fmt: The format string to use
3038  * @...: Arguments for the format string
3039  *
3040  * The function returns the number of characters written
3041  * into @buf. Use snprintf() or scnprintf() in order to avoid
3042  * buffer overflows.
3043  *
3044  * See the vsnprintf() documentation for format string extensions over C99.
3045  */
3046 int sprintf(char *buf, const char *fmt, ...)
3047 {
3048 	va_list args;
3049 	int i;
3050 
3051 	va_start(args, fmt);
3052 	i = vsnprintf(buf, INT_MAX, fmt, args);
3053 	va_end(args);
3054 
3055 	return i;
3056 }
3057 EXPORT_SYMBOL(sprintf);
3058 
3059 #ifdef CONFIG_BINARY_PRINTF
3060 /*
3061  * bprintf service:
3062  * vbin_printf() - VA arguments to binary data
3063  * bstr_printf() - Binary data to text string
3064  */
3065 
3066 /**
3067  * vbin_printf - Parse a format string and place args' binary value in a buffer
3068  * @bin_buf: The buffer to place args' binary value
3069  * @size: The size of the buffer(by words(32bits), not characters)
3070  * @fmt: The format string to use
3071  * @args: Arguments for the format string
3072  *
3073  * The format follows C99 vsnprintf, except %n is ignored, and its argument
3074  * is skipped.
3075  *
3076  * The return value is the number of words(32bits) which would be generated for
3077  * the given input.
3078  *
3079  * NOTE:
3080  * If the return value is greater than @size, the resulting bin_buf is NOT
3081  * valid for bstr_printf().
3082  */
3083 int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args)
3084 {
3085 	struct printf_spec spec = {0};
3086 	char *str, *end;
3087 	int width;
3088 
3089 	str = (char *)bin_buf;
3090 	end = (char *)(bin_buf + size);
3091 
3092 #define save_arg(type)							\
3093 ({									\
3094 	unsigned long long value;					\
3095 	if (sizeof(type) == 8) {					\
3096 		unsigned long long val8;				\
3097 		str = PTR_ALIGN(str, sizeof(u32));			\
3098 		val8 = va_arg(args, unsigned long long);		\
3099 		if (str + sizeof(type) <= end) {			\
3100 			*(u32 *)str = *(u32 *)&val8;			\
3101 			*(u32 *)(str + 4) = *((u32 *)&val8 + 1);	\
3102 		}							\
3103 		value = val8;						\
3104 	} else {							\
3105 		unsigned int val4;					\
3106 		str = PTR_ALIGN(str, sizeof(type));			\
3107 		val4 = va_arg(args, int);				\
3108 		if (str + sizeof(type) <= end)				\
3109 			*(typeof(type) *)str = (type)(long)val4;	\
3110 		value = (unsigned long long)val4;			\
3111 	}								\
3112 	str += sizeof(type);						\
3113 	value;								\
3114 })
3115 
3116 	while (*fmt) {
3117 		int read = format_decode(fmt, &spec);
3118 
3119 		fmt += read;
3120 
3121 		switch (spec.type) {
3122 		case FORMAT_TYPE_NONE:
3123 		case FORMAT_TYPE_PERCENT_CHAR:
3124 			break;
3125 		case FORMAT_TYPE_INVALID:
3126 			goto out;
3127 
3128 		case FORMAT_TYPE_WIDTH:
3129 		case FORMAT_TYPE_PRECISION:
3130 			width = (int)save_arg(int);
3131 			/* Pointers may require the width */
3132 			if (*fmt == 'p')
3133 				set_field_width(&spec, width);
3134 			break;
3135 
3136 		case FORMAT_TYPE_CHAR:
3137 			save_arg(char);
3138 			break;
3139 
3140 		case FORMAT_TYPE_STR: {
3141 			const char *save_str = va_arg(args, char *);
3142 			const char *err_msg;
3143 			size_t len;
3144 
3145 			err_msg = check_pointer_msg(save_str);
3146 			if (err_msg)
3147 				save_str = err_msg;
3148 
3149 			len = strlen(save_str) + 1;
3150 			if (str + len < end)
3151 				memcpy(str, save_str, len);
3152 			str += len;
3153 			break;
3154 		}
3155 
3156 		case FORMAT_TYPE_PTR:
3157 			/* Dereferenced pointers must be done now */
3158 			switch (*fmt) {
3159 			/* Dereference of functions is still OK */
3160 			case 'S':
3161 			case 's':
3162 			case 'x':
3163 			case 'K':
3164 			case 'e':
3165 				save_arg(void *);
3166 				break;
3167 			default:
3168 				if (!isalnum(*fmt)) {
3169 					save_arg(void *);
3170 					break;
3171 				}
3172 				str = pointer(fmt, str, end, va_arg(args, void *),
3173 					      spec);
3174 				if (str + 1 < end)
3175 					*str++ = '\0';
3176 				else
3177 					end[-1] = '\0'; /* Must be nul terminated */
3178 			}
3179 			/* skip all alphanumeric pointer suffixes */
3180 			while (isalnum(*fmt))
3181 				fmt++;
3182 			break;
3183 
3184 		default:
3185 			switch (spec.type) {
3186 
3187 			case FORMAT_TYPE_LONG_LONG:
3188 				save_arg(long long);
3189 				break;
3190 			case FORMAT_TYPE_ULONG:
3191 			case FORMAT_TYPE_LONG:
3192 				save_arg(unsigned long);
3193 				break;
3194 			case FORMAT_TYPE_SIZE_T:
3195 				save_arg(size_t);
3196 				break;
3197 			case FORMAT_TYPE_PTRDIFF:
3198 				save_arg(ptrdiff_t);
3199 				break;
3200 			case FORMAT_TYPE_UBYTE:
3201 			case FORMAT_TYPE_BYTE:
3202 				save_arg(char);
3203 				break;
3204 			case FORMAT_TYPE_USHORT:
3205 			case FORMAT_TYPE_SHORT:
3206 				save_arg(short);
3207 				break;
3208 			default:
3209 				save_arg(int);
3210 			}
3211 		}
3212 	}
3213 
3214 out:
3215 	return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf;
3216 #undef save_arg
3217 }
3218 EXPORT_SYMBOL_GPL(vbin_printf);
3219 
3220 /**
3221  * bstr_printf - Format a string from binary arguments and place it in a buffer
3222  * @buf: The buffer to place the result into
3223  * @size: The size of the buffer, including the trailing null space
3224  * @fmt: The format string to use
3225  * @bin_buf: Binary arguments for the format string
3226  *
3227  * This function like C99 vsnprintf, but the difference is that vsnprintf gets
3228  * arguments from stack, and bstr_printf gets arguments from @bin_buf which is
3229  * a binary buffer that generated by vbin_printf.
3230  *
3231  * The format follows C99 vsnprintf, but has some extensions:
3232  *  see vsnprintf comment for details.
3233  *
3234  * The return value is the number of characters which would
3235  * be generated for the given input, excluding the trailing
3236  * '\0', as per ISO C99. If you want to have the exact
3237  * number of characters written into @buf as return value
3238  * (not including the trailing '\0'), use vscnprintf(). If the
3239  * return is greater than or equal to @size, the resulting
3240  * string is truncated.
3241  */
3242 int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
3243 {
3244 	struct printf_spec spec = {0};
3245 	char *str, *end;
3246 	const char *args = (const char *)bin_buf;
3247 
3248 	if (WARN_ON_ONCE(size > INT_MAX))
3249 		return 0;
3250 
3251 	str = buf;
3252 	end = buf + size;
3253 
3254 #define get_arg(type)							\
3255 ({									\
3256 	typeof(type) value;						\
3257 	if (sizeof(type) == 8) {					\
3258 		args = PTR_ALIGN(args, sizeof(u32));			\
3259 		*(u32 *)&value = *(u32 *)args;				\
3260 		*((u32 *)&value + 1) = *(u32 *)(args + 4);		\
3261 	} else {							\
3262 		args = PTR_ALIGN(args, sizeof(type));			\
3263 		value = *(typeof(type) *)args;				\
3264 	}								\
3265 	args += sizeof(type);						\
3266 	value;								\
3267 })
3268 
3269 	/* Make sure end is always >= buf */
3270 	if (end < buf) {
3271 		end = ((void *)-1);
3272 		size = end - buf;
3273 	}
3274 
3275 	while (*fmt) {
3276 		const char *old_fmt = fmt;
3277 		int read = format_decode(fmt, &spec);
3278 
3279 		fmt += read;
3280 
3281 		switch (spec.type) {
3282 		case FORMAT_TYPE_NONE: {
3283 			int copy = read;
3284 			if (str < end) {
3285 				if (copy > end - str)
3286 					copy = end - str;
3287 				memcpy(str, old_fmt, copy);
3288 			}
3289 			str += read;
3290 			break;
3291 		}
3292 
3293 		case FORMAT_TYPE_WIDTH:
3294 			set_field_width(&spec, get_arg(int));
3295 			break;
3296 
3297 		case FORMAT_TYPE_PRECISION:
3298 			set_precision(&spec, get_arg(int));
3299 			break;
3300 
3301 		case FORMAT_TYPE_CHAR: {
3302 			char c;
3303 
3304 			if (!(spec.flags & LEFT)) {
3305 				while (--spec.field_width > 0) {
3306 					if (str < end)
3307 						*str = ' ';
3308 					++str;
3309 				}
3310 			}
3311 			c = (unsigned char) get_arg(char);
3312 			if (str < end)
3313 				*str = c;
3314 			++str;
3315 			while (--spec.field_width > 0) {
3316 				if (str < end)
3317 					*str = ' ';
3318 				++str;
3319 			}
3320 			break;
3321 		}
3322 
3323 		case FORMAT_TYPE_STR: {
3324 			const char *str_arg = args;
3325 			args += strlen(str_arg) + 1;
3326 			str = string(str, end, (char *)str_arg, spec);
3327 			break;
3328 		}
3329 
3330 		case FORMAT_TYPE_PTR: {
3331 			bool process = false;
3332 			int copy, len;
3333 			/* Non function dereferences were already done */
3334 			switch (*fmt) {
3335 			case 'S':
3336 			case 's':
3337 			case 'x':
3338 			case 'K':
3339 			case 'e':
3340 				process = true;
3341 				break;
3342 			default:
3343 				if (!isalnum(*fmt)) {
3344 					process = true;
3345 					break;
3346 				}
3347 				/* Pointer dereference was already processed */
3348 				if (str < end) {
3349 					len = copy = strlen(args);
3350 					if (copy > end - str)
3351 						copy = end - str;
3352 					memcpy(str, args, copy);
3353 					str += len;
3354 					args += len + 1;
3355 				}
3356 			}
3357 			if (process)
3358 				str = pointer(fmt, str, end, get_arg(void *), spec);
3359 
3360 			while (isalnum(*fmt))
3361 				fmt++;
3362 			break;
3363 		}
3364 
3365 		case FORMAT_TYPE_PERCENT_CHAR:
3366 			if (str < end)
3367 				*str = '%';
3368 			++str;
3369 			break;
3370 
3371 		case FORMAT_TYPE_INVALID:
3372 			goto out;
3373 
3374 		default: {
3375 			unsigned long long num;
3376 
3377 			switch (spec.type) {
3378 
3379 			case FORMAT_TYPE_LONG_LONG:
3380 				num = get_arg(long long);
3381 				break;
3382 			case FORMAT_TYPE_ULONG:
3383 			case FORMAT_TYPE_LONG:
3384 				num = get_arg(unsigned long);
3385 				break;
3386 			case FORMAT_TYPE_SIZE_T:
3387 				num = get_arg(size_t);
3388 				break;
3389 			case FORMAT_TYPE_PTRDIFF:
3390 				num = get_arg(ptrdiff_t);
3391 				break;
3392 			case FORMAT_TYPE_UBYTE:
3393 				num = get_arg(unsigned char);
3394 				break;
3395 			case FORMAT_TYPE_BYTE:
3396 				num = get_arg(signed char);
3397 				break;
3398 			case FORMAT_TYPE_USHORT:
3399 				num = get_arg(unsigned short);
3400 				break;
3401 			case FORMAT_TYPE_SHORT:
3402 				num = get_arg(short);
3403 				break;
3404 			case FORMAT_TYPE_UINT:
3405 				num = get_arg(unsigned int);
3406 				break;
3407 			default:
3408 				num = get_arg(int);
3409 			}
3410 
3411 			str = number(str, end, num, spec);
3412 		} /* default: */
3413 		} /* switch(spec.type) */
3414 	} /* while(*fmt) */
3415 
3416 out:
3417 	if (size > 0) {
3418 		if (str < end)
3419 			*str = '\0';
3420 		else
3421 			end[-1] = '\0';
3422 	}
3423 
3424 #undef get_arg
3425 
3426 	/* the trailing null byte doesn't count towards the total */
3427 	return str - buf;
3428 }
3429 EXPORT_SYMBOL_GPL(bstr_printf);
3430 
3431 #endif /* CONFIG_BINARY_PRINTF */
3432 
3433 /**
3434  * vsscanf - Unformat a buffer into a list of arguments
3435  * @buf:	input buffer
3436  * @fmt:	format of buffer
3437  * @args:	arguments
3438  */
3439 int vsscanf(const char *buf, const char *fmt, va_list args)
3440 {
3441 	const char *str = buf;
3442 	char *next;
3443 	char digit;
3444 	int num = 0;
3445 	u8 qualifier;
3446 	unsigned int base;
3447 	union {
3448 		long long s;
3449 		unsigned long long u;
3450 	} val;
3451 	s16 field_width;
3452 	bool is_sign;
3453 
3454 	while (*fmt) {
3455 		/* skip any white space in format */
3456 		/* white space in format matches any amount of
3457 		 * white space, including none, in the input.
3458 		 */
3459 		if (isspace(*fmt)) {
3460 			fmt = skip_spaces(++fmt);
3461 			str = skip_spaces(str);
3462 		}
3463 
3464 		/* anything that is not a conversion must match exactly */
3465 		if (*fmt != '%' && *fmt) {
3466 			if (*fmt++ != *str++)
3467 				break;
3468 			continue;
3469 		}
3470 
3471 		if (!*fmt)
3472 			break;
3473 		++fmt;
3474 
3475 		/* skip this conversion.
3476 		 * advance both strings to next white space
3477 		 */
3478 		if (*fmt == '*') {
3479 			if (!*str)
3480 				break;
3481 			while (!isspace(*fmt) && *fmt != '%' && *fmt) {
3482 				/* '%*[' not yet supported, invalid format */
3483 				if (*fmt == '[')
3484 					return num;
3485 				fmt++;
3486 			}
3487 			while (!isspace(*str) && *str)
3488 				str++;
3489 			continue;
3490 		}
3491 
3492 		/* get field width */
3493 		field_width = -1;
3494 		if (isdigit(*fmt)) {
3495 			field_width = skip_atoi(&fmt);
3496 			if (field_width <= 0)
3497 				break;
3498 		}
3499 
3500 		/* get conversion qualifier */
3501 		qualifier = -1;
3502 		if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
3503 		    *fmt == 'z') {
3504 			qualifier = *fmt++;
3505 			if (unlikely(qualifier == *fmt)) {
3506 				if (qualifier == 'h') {
3507 					qualifier = 'H';
3508 					fmt++;
3509 				} else if (qualifier == 'l') {
3510 					qualifier = 'L';
3511 					fmt++;
3512 				}
3513 			}
3514 		}
3515 
3516 		if (!*fmt)
3517 			break;
3518 
3519 		if (*fmt == 'n') {
3520 			/* return number of characters read so far */
3521 			*va_arg(args, int *) = str - buf;
3522 			++fmt;
3523 			continue;
3524 		}
3525 
3526 		if (!*str)
3527 			break;
3528 
3529 		base = 10;
3530 		is_sign = false;
3531 
3532 		switch (*fmt++) {
3533 		case 'c':
3534 		{
3535 			char *s = (char *)va_arg(args, char*);
3536 			if (field_width == -1)
3537 				field_width = 1;
3538 			do {
3539 				*s++ = *str++;
3540 			} while (--field_width > 0 && *str);
3541 			num++;
3542 		}
3543 		continue;
3544 		case 's':
3545 		{
3546 			char *s = (char *)va_arg(args, char *);
3547 			if (field_width == -1)
3548 				field_width = SHRT_MAX;
3549 			/* first, skip leading white space in buffer */
3550 			str = skip_spaces(str);
3551 
3552 			/* now copy until next white space */
3553 			while (*str && !isspace(*str) && field_width--)
3554 				*s++ = *str++;
3555 			*s = '\0';
3556 			num++;
3557 		}
3558 		continue;
3559 		/*
3560 		 * Warning: This implementation of the '[' conversion specifier
3561 		 * deviates from its glibc counterpart in the following ways:
3562 		 * (1) It does NOT support ranges i.e. '-' is NOT a special
3563 		 *     character
3564 		 * (2) It cannot match the closing bracket ']' itself
3565 		 * (3) A field width is required
3566 		 * (4) '%*[' (discard matching input) is currently not supported
3567 		 *
3568 		 * Example usage:
3569 		 * ret = sscanf("00:0a:95","%2[^:]:%2[^:]:%2[^:]",
3570 		 *		buf1, buf2, buf3);
3571 		 * if (ret < 3)
3572 		 *    // etc..
3573 		 */
3574 		case '[':
3575 		{
3576 			char *s = (char *)va_arg(args, char *);
3577 			DECLARE_BITMAP(set, 256) = {0};
3578 			unsigned int len = 0;
3579 			bool negate = (*fmt == '^');
3580 
3581 			/* field width is required */
3582 			if (field_width == -1)
3583 				return num;
3584 
3585 			if (negate)
3586 				++fmt;
3587 
3588 			for ( ; *fmt && *fmt != ']'; ++fmt, ++len)
3589 				__set_bit((u8)*fmt, set);
3590 
3591 			/* no ']' or no character set found */
3592 			if (!*fmt || !len)
3593 				return num;
3594 			++fmt;
3595 
3596 			if (negate) {
3597 				bitmap_complement(set, set, 256);
3598 				/* exclude null '\0' byte */
3599 				__clear_bit(0, set);
3600 			}
3601 
3602 			/* match must be non-empty */
3603 			if (!test_bit((u8)*str, set))
3604 				return num;
3605 
3606 			while (test_bit((u8)*str, set) && field_width--)
3607 				*s++ = *str++;
3608 			*s = '\0';
3609 			++num;
3610 		}
3611 		continue;
3612 		case 'o':
3613 			base = 8;
3614 			break;
3615 		case 'x':
3616 		case 'X':
3617 			base = 16;
3618 			break;
3619 		case 'i':
3620 			base = 0;
3621 			fallthrough;
3622 		case 'd':
3623 			is_sign = true;
3624 			fallthrough;
3625 		case 'u':
3626 			break;
3627 		case '%':
3628 			/* looking for '%' in str */
3629 			if (*str++ != '%')
3630 				return num;
3631 			continue;
3632 		default:
3633 			/* invalid format; stop here */
3634 			return num;
3635 		}
3636 
3637 		/* have some sort of integer conversion.
3638 		 * first, skip white space in buffer.
3639 		 */
3640 		str = skip_spaces(str);
3641 
3642 		digit = *str;
3643 		if (is_sign && digit == '-') {
3644 			if (field_width == 1)
3645 				break;
3646 
3647 			digit = *(str + 1);
3648 		}
3649 
3650 		if (!digit
3651 		    || (base == 16 && !isxdigit(digit))
3652 		    || (base == 10 && !isdigit(digit))
3653 		    || (base == 8 && !isodigit(digit))
3654 		    || (base == 0 && !isdigit(digit)))
3655 			break;
3656 
3657 		if (is_sign)
3658 			val.s = simple_strntoll(str, &next, base,
3659 						field_width >= 0 ? field_width : INT_MAX);
3660 		else
3661 			val.u = simple_strntoull(str, &next, base,
3662 						 field_width >= 0 ? field_width : INT_MAX);
3663 
3664 		switch (qualifier) {
3665 		case 'H':	/* that's 'hh' in format */
3666 			if (is_sign)
3667 				*va_arg(args, signed char *) = val.s;
3668 			else
3669 				*va_arg(args, unsigned char *) = val.u;
3670 			break;
3671 		case 'h':
3672 			if (is_sign)
3673 				*va_arg(args, short *) = val.s;
3674 			else
3675 				*va_arg(args, unsigned short *) = val.u;
3676 			break;
3677 		case 'l':
3678 			if (is_sign)
3679 				*va_arg(args, long *) = val.s;
3680 			else
3681 				*va_arg(args, unsigned long *) = val.u;
3682 			break;
3683 		case 'L':
3684 			if (is_sign)
3685 				*va_arg(args, long long *) = val.s;
3686 			else
3687 				*va_arg(args, unsigned long long *) = val.u;
3688 			break;
3689 		case 'z':
3690 			*va_arg(args, size_t *) = val.u;
3691 			break;
3692 		default:
3693 			if (is_sign)
3694 				*va_arg(args, int *) = val.s;
3695 			else
3696 				*va_arg(args, unsigned int *) = val.u;
3697 			break;
3698 		}
3699 		num++;
3700 
3701 		if (!next)
3702 			break;
3703 		str = next;
3704 	}
3705 
3706 	return num;
3707 }
3708 EXPORT_SYMBOL(vsscanf);
3709 
3710 /**
3711  * sscanf - Unformat a buffer into a list of arguments
3712  * @buf:	input buffer
3713  * @fmt:	formatting of buffer
3714  * @...:	resulting arguments
3715  */
3716 int sscanf(const char *buf, const char *fmt, ...)
3717 {
3718 	va_list args;
3719 	int i;
3720 
3721 	va_start(args, fmt);
3722 	i = vsscanf(buf, fmt, args);
3723 	va_end(args);
3724 
3725 	return i;
3726 }
3727 EXPORT_SYMBOL(sscanf);
3728